diff --git a/utils/include/window_helper.h b/utils/include/window_helper.h
index 7d8afdb3..bca9272f 100644
--- a/utils/include/window_helper.h
+++ b/utils/include/window_helper.h
@@ -64,6 +64,11 @@ public:
             mode == WindowMode::WINDOW_MODE_PIP;
     }
 
+    static inline bool IsEmptyRect(const Rect& r)
+    {
+        return (r.posX_ == 0 && r.posY_ == 0 && r.width_ == 0 && r.height_ == 0);
+    }
+
     WindowHelper() = default;
     ~WindowHelper() = default;
 };
diff --git a/wm/src/window_impl.cpp b/wm/src/window_impl.cpp
index 2fccd1e0..378fecf7 100644
--- a/wm/src/window_impl.cpp
+++ b/wm/src/window_impl.cpp
@@ -213,11 +213,6 @@ WMError WindowImpl::SetUIContent(const std::string& contentInfo,
         WLOGFE("fail to SetUIContent id: %{public}d", property_->GetWindowId());
         return WMError::WM_ERROR_NULLPTR;
     }
-    if (WindowHelper::IsMainWindow(property_->GetWindowType())) {
-        property_->SetDecorEnable(true);
-    } else {
-        property_->SetDecorEnable(false);
-    }
     if (isdistributed) {
         uiContent_->Restore(this, contentInfo, storage);
     } else {
@@ -281,6 +276,12 @@ WMError WindowImpl::Create(const std::string& parentName, const std::shared_ptr<
         }
     }
 
+    if (WindowHelper::IsMainWindow(property_->GetWindowType())) {
+        property_->SetDecorEnable(true);
+    } else {
+        property_->SetDecorEnable(false);
+    }
+
     sptr<WindowImpl> window(this);
     sptr<IWindow> windowAgent(new WindowAgent(window));
     uint32_t windowId = 0;
diff --git a/wmserver/include/window_layout_policy.h b/wmserver/include/window_layout_policy.h
index c63ee4b0..c1f005f5 100644
--- a/wmserver/include/window_layout_policy.h
+++ b/wmserver/include/window_layout_policy.h
@@ -54,6 +54,7 @@ public:
     void UpdateWindowNode(sptr<WindowNode>& node);
     void UpdateLayoutRect(sptr<WindowNode>& node);
     Rect GetDependDisplayRects() const;
+    void UpdateDefaultFoatingRect();
 
 private:
     LayoutDependRects dependRects;
@@ -78,6 +79,9 @@ private:
     Rect& GetLimitRect(const WindowMode mode);
     Rect& GetDisplayRect(const WindowMode mode);
     void LimitMoveBounds(Rect& rect);
+    void LimitWindowSize(const sptr<WindowNode>& node, const Rect& displayRect, Rect& winRect);
+    void SetRectForFloating(const sptr<WindowNode>& node);
+    Rect defaultFloatingRect_ = { 0, 0, 0, 0 };
 };
 }
 }
diff --git a/wmserver/include/window_node.h b/wmserver/include/window_node.h
index 4dc76246..e7f18bbb 100644
--- a/wmserver/include/window_node.h
+++ b/wmserver/include/window_node.h
@@ -42,6 +42,7 @@ public:
 
     void SetDisplayId(int32_t displayId);
     void SetLayoutRect(const Rect& rect);
+    void SetWindowRect(const Rect& rect);
     void SetWindowProperty(const sptr<WindowProperty>& property);
     void SetSystemBarProperty(WindowType type, const SystemBarProperty& property);
     void SetWindowMode(WindowMode mode);
diff --git a/wmserver/src/window_layout_policy.cpp b/wmserver/src/window_layout_policy.cpp
index a6a78cd2..619d30a0 100644
--- a/wmserver/src/window_layout_policy.cpp
+++ b/wmserver/src/window_layout_policy.cpp
@@ -24,6 +24,8 @@ namespace {
     constexpr HiviewDFX::HiLogLabel LABEL = {LOG_CORE, 0, "WindowLayoutPolicy"};
     constexpr uint32_t WINDOW_TITLE_BAR_HEIGHT = 48;
     constexpr uint32_t WINDOW_FRAME_WIDTH = 4;
+    constexpr uint32_t MIN_VERTICAL_FLOATING_WIDTH = 360;
+    constexpr uint32_t MIN_VERTICAL_FLOATING_HEIGHT = 480;
 }
 
 WindowLayoutPolicy::WindowLayoutPolicy(const sptr<WindowNode>& belowAppNode,
@@ -42,6 +44,7 @@ void WindowLayoutPolicy::UpdateDisplayInfo(const Rect& primaryRect,
     dependRects.secRect_ = secondaryRect;
     dependRects.fullRect_ = displayRect;
     InitLimitRects();
+    UpdateDefaultFoatingRect();
 }
 
 void WindowLayoutPolicy::LayoutWindowTree()
@@ -78,9 +81,48 @@ void WindowLayoutPolicy::LayoutWindowNode(sptr<WindowNode>& node)
 void WindowLayoutPolicy::AddWindowNode(sptr<WindowNode>& node)
 {
     WM_FUNCTION_TRACE();
+    if (WindowHelper::IsEmptyRect(node->GetWindowProperty()->GetWindowRect())) {
+        SetRectForFloating(node);
+    }
     UpdateWindowNode(node); // currently, update and add do the same process
 }
 
+void WindowLayoutPolicy::UpdateDefaultFoatingRect()
+{
+    constexpr uint32_t half = 2;
+    constexpr float ratio = 0.75;  // 0.75: default height/width ratio
+
+    // calculate default H and w
+    Rect displayRect = GetDisplayRect(WindowMode::WINDOW_MODE_FLOATING);
+    uint32_t defaultW = static_cast<uint32_t>(displayRect.width_ * ratio);
+    uint32_t defaultH = static_cast<uint32_t>(displayRect.height_ * ratio);
+
+    // calculate default x and y
+    Rect limitRect = GetLimitRect(WindowMode::WINDOW_MODE_FLOATING);
+    Rect resRect = {0, 0, defaultW, defaultH};
+    if (defaultW <= limitRect.width_ && defaultH <= limitRect.height_) {
+        int32_t centerPosX = limitRect.posX_ + static_cast<int32_t>(limitRect.width_ / half);
+        resRect.posX_ = centerPosX - static_cast<int32_t>(defaultW / half);
+
+        int32_t centerPosY = limitRect.posY_ + static_cast<int32_t>(limitRect.height_ / half);
+        resRect.posY_ = centerPosY - static_cast<int32_t>(defaultH / half);
+    }
+
+    defaultFloatingRect_ = resRect;
+}
+
+void WindowLayoutPolicy::SetRectForFloating(const sptr<WindowNode>& node)
+{
+    // deduct decor size
+    Rect rect = defaultFloatingRect_;
+    if (node->GetWindowProperty()->GetDecorEnable()) {
+        rect.width_ -= (WINDOW_FRAME_WIDTH + WINDOW_FRAME_WIDTH);
+        rect.height_ -= (WINDOW_TITLE_BAR_HEIGHT + WINDOW_FRAME_WIDTH);
+    }
+
+    node->SetWindowRect(rect);
+}
+
 void WindowLayoutPolicy::RemoveWindowNode(sptr<WindowNode>& node)
 {
     WM_FUNCTION_TRACE();
@@ -158,6 +200,7 @@ void WindowLayoutPolicy::UpdateLayoutRect(sptr<WindowNode>& node)
     auto type = node->GetWindowType();
     auto mode = node->GetWindowMode();
     auto flags = node->GetWindowFlags();
+    auto decorEnbale = node->GetWindowProperty()->GetDecorEnable();
     bool needAvoid = (flags & static_cast<uint32_t>(WindowFlag::WINDOW_FLAG_NEED_AVOID));
     bool parentLimit = (flags & static_cast<uint32_t>(WindowFlag::WINDOW_FLAG_PARENT_LIMIT));
     bool subWindow = WindowHelper::IsSubWindow(type);
@@ -168,9 +211,9 @@ void WindowLayoutPolicy::UpdateLayoutRect(sptr<WindowNode>& node)
     Rect limitRect = displayRect;
     Rect winRect = node->GetWindowProperty()->GetWindowRect();
 
-    WLOGFI("Id:%{public}d, avoid:%{public}d parLimit:%{public}d floating:%{public}d, sub:%{public}d," \
-        "type:%{public}d, requestRect:[%{public}d, %{public}d, %{public}d, %{public}d]",
-        node->GetWindowId(), needAvoid, parentLimit, floatingWindow, subWindow,
+    WLOGFI("Id:%{public}d, avoid:%{public}d parLimit:%{public}d floating:%{public}d, sub:%{public}d, " \
+        "deco:%{public}d, type:%{public}d, requestRect:[%{public}d, %{public}d, %{public}d, %{public}d]",
+        node->GetWindowId(), needAvoid, parentLimit, floatingWindow, subWindow, decorEnbale,
         static_cast<uint32_t>(type), winRect.posX_, winRect.posY_, winRect.width_, winRect.height_);
     if (needAvoid) {
         limitRect = GetLimitRect(mode);
@@ -188,10 +231,7 @@ void WindowLayoutPolicy::UpdateLayoutRect(sptr<WindowNode>& node)
         }
     }
     // Limit window to the maximum window size
-    winRect.width_ = std::min(displayRect.width_, winRect.width_);
-    winRect.height_ = std::min(displayRect.height_, winRect.height_);
-    winRect.width_ = std::max(1u, winRect.width_);
-    winRect.height_ = std::max(1u, winRect.height_);
+    LimitWindowSize(node, displayRect, winRect);
 
     if (node->GetWindowType() == WindowType::WINDOW_TYPE_DOCK_SLICE) {
         LimitMoveBounds(winRect);
@@ -204,6 +244,28 @@ void WindowLayoutPolicy::UpdateLayoutRect(sptr<WindowNode>& node)
     }
 }
 
+void WindowLayoutPolicy::LimitWindowSize(const sptr<WindowNode>& node, const Rect& displayRect, Rect& winRect)
+{
+    bool floatingWindow = (node->GetWindowMode() == WindowMode::WINDOW_MODE_FLOATING);
+
+    winRect.width_ = std::min(displayRect.width_, winRect.width_);
+    winRect.height_ = std::min(displayRect.height_, winRect.height_);
+    bool isVertical = (displayRect.height_ > displayRect.width_) ? true : false;
+    WindowType windowType = node->GetWindowProperty()->GetWindowType();
+    if (floatingWindow && !WindowHelper::IsSystemWindow(windowType)) {
+        if (isVertical) {
+            winRect.width_ = std::max(MIN_VERTICAL_FLOATING_WIDTH, winRect.width_);
+            winRect.height_ = std::max(MIN_VERTICAL_FLOATING_HEIGHT, winRect.height_);
+        } else {
+            winRect.width_ = std::max(MIN_VERTICAL_FLOATING_HEIGHT, winRect.width_);
+            winRect.height_ = std::max(MIN_VERTICAL_FLOATING_WIDTH, winRect.height_);
+        }
+    } else {
+        winRect.width_ = std::max(1u, winRect.width_);
+        winRect.height_ = std::max(1u, winRect.height_);
+    }
+}
+
 AvoidPosType WindowLayoutPolicy::GetAvoidPosType(const Rect& rect)
 {
     if (rect.width_ >=  rect.height_) {
diff --git a/wmserver/src/window_node.cpp b/wmserver/src/window_node.cpp
index c7abd188..4c4f8916 100644
--- a/wmserver/src/window_node.cpp
+++ b/wmserver/src/window_node.cpp
@@ -28,6 +28,11 @@ void WindowNode::SetLayoutRect(const Rect& rect)
     layoutRect_ = rect;
 }
 
+void WindowNode::SetWindowRect(const Rect& rect)
+{
+    property_->SetWindowRect(rect);
+}
+
 void WindowNode::SetWindowProperty(const sptr<WindowProperty>& property)
 {
     property_ = property;
diff --git a/wmserver/src/window_node_container.cpp b/wmserver/src/window_node_container.cpp
index 739c7064..bec4694b 100644
--- a/wmserver/src/window_node_container.cpp
+++ b/wmserver/src/window_node_container.cpp
@@ -602,6 +602,7 @@ std::vector<Rect> WindowNodeContainer::GetAvoidAreaByType(AvoidAreaType avoidAre
 
 void WindowNodeContainer::OnAvoidAreaChange(const std::vector<Rect>& avoidArea)
 {
+    layoutPolicy_->UpdateDefaultFoatingRect();
     for (auto& node : appWindowNode_->children_) {
         if (node->GetWindowMode() == WindowMode::WINDOW_MODE_FULLSCREEN && node->GetWindowToken() != nullptr) {
             // notify client