diff --git a/demo/Semi.Avalonia.Demo/Pages/CalendarDatePickerDemo.axaml b/demo/Semi.Avalonia.Demo/Pages/CalendarDatePickerDemo.axaml
index ca8b258..ca8438f 100644
--- a/demo/Semi.Avalonia.Demo/Pages/CalendarDatePickerDemo.axaml
+++ b/demo/Semi.Avalonia.Demo/Pages/CalendarDatePickerDemo.axaml
@@ -9,6 +9,7 @@
     mc:Ignorable="d">
     <StackPanel HorizontalAlignment="Left" Spacing="20">
         <CalendarDatePicker />
+        <CalendarDatePicker Width="500" />
         <CalendarDatePicker Classes="Large" />
         <CalendarDatePicker Classes="Small" />
         <CalendarDatePicker
diff --git a/src/Semi.Avalonia/Controls/CalendarDatePicker.axaml b/src/Semi.Avalonia/Controls/CalendarDatePicker.axaml
index 48b12c5..7213b36 100644
--- a/src/Semi.Avalonia/Controls/CalendarDatePicker.axaml
+++ b/src/Semi.Avalonia/Controls/CalendarDatePicker.axaml
@@ -49,7 +49,7 @@
                         BorderThickness="{TemplateBinding BorderThickness}"
                         CornerRadius="{TemplateBinding CornerRadius}">
                         <Grid
-                            HorizontalAlignment="Left"
+                            HorizontalAlignment="Stretch"
                             VerticalAlignment="Center"
                             ColumnDefinitions="*,Auto">
                             <TextBox