Have a look at this
<Window
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
x:Class="WpfApplication3.MainWindow"
x:Name="Window"
Title="MainWindow"
Width="640" Height="480" Background="white">
<LinearGradientBrush x:Key="LinearGradient_Orange_H" EndPoint="0,1" StartPoint="0,0">
<GradientStop Color="#FFF9FF09" Offset="0"/>
<GradientStop Color="#FFF7DE25" Offset="0.959"/>
<GradientStop Color="#FFFF7000" Offset="0.033"/>
<GradientStop Color="#FFFF7200" Offset="1"/>
</LinearGradientBrush>
<LinearGradientBrush x:Key="Horizontal_Gradient" EndPoint="1,0" StartPoint="0,0">
<GradientStop Color="#CCC" Offset="0.0"/>
<GradientStop Color="#444" Offset="1.0"/>
</LinearGradientBrush>
<LinearGradientBrush x:Key="Vertical_Gradient" EndPoint="0,1" StartPoint="0,0">
<GradientStop Color="#CCC" Offset="0.0"/>
<GradientStop Color="#444" Offset="1.0"/>
</LinearGradientBrush>
<!-- MouseOverBrush is used for MouseOver in Button, Radio Button, CheckBox -->
<LinearGradientBrush x:Key="MouseOverBrush" EndPoint="0,1" StartPoint="0,0">
<GradientStop Color="#FFF" Offset="0.0"/>
<GradientStop Color="#AAA" Offset="1.0"/>
</LinearGradientBrush>
<!-- LightBrush is used for content areas such as Menu, Tab Control background -->
<LinearGradientBrush EndPoint="0,1" StartPoint="0,0" x:Key="LightBrush">
<GradientStop Color="#FFF" Offset="0.0"/>
<GradientStop Color="#EEE" Offset="1.0"/>
</LinearGradientBrush>
<Style x:Key="{x:Type CheckBox}" TargetType="{x:Type CheckBox}">
<Setter Property="SnapsToDevicePixels" Value="true"/>
<Setter Property="Background" Value="{DynamicResource NormalBrush}"/>
<Setter Property="BorderBrush" Value="{DynamicResource NormalBorderBrush}"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type CheckBox}">
<!-- BulletDecorator is used to provide baseline alignment between the checkmark and the Content -->
<BulletDecorator Background="Transparent">
<BulletDecorator.Bullet>
<Grid Width="13" Height="13">
<Border x:Name="Border" Background="{DynamicResource LightBrush}" BorderBrush="{DynamicResource Stroke_Gradient}" BorderThickness="1,1,1,1" CornerRadius="1,1,1,1"/>
<Path x:Name="CheckMark" Stroke="{DynamicResource Normal_Background}" StrokeThickness="3" SnapsToDevicePixels="False" Data="M1.5000001,1.5833334 L9.7920001,9.6666667 M1.5420001,9.6666667 L9.7083333,1.5000001" Margin="0.875,0.895,0.833,0.938" ClipToBounds="False" StrokeEndLineCap="Round" StrokeStartLineCap="Round"/>
</Grid>
</BulletDecorator.Bullet>
<ContentPresenter HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}" Margin="{TemplateBinding Padding}" VerticalAlignment="{TemplateBinding VerticalContentAlignment}" RecognizesAccessKey="True"/>
</BulletDecorator>
<!-- This uses Visibility to hide and show the CheckMark on IsChecked -->
<ControlTemplate.Triggers>
<Trigger Property="IsChecked" Value="false">
<Setter Property="Visibility" Value="Collapsed" TargetName="CheckMark"/>
</Trigger>
<Trigger Property="IsMouseOver" Value="true">
<Setter Property="Background" Value="{DynamicResource MouseOverBrush}" TargetName="Border"/>
</Trigger>
<Trigger Property="IsPressed" Value="true">
<Setter Property="Background" Value="{DynamicResource Normal_Background}" TargetName="Border"/>
<Setter Property="BorderBrush" Value="{DynamicResource PressedBorderBrush}" TargetName="Border"/>
</Trigger>
<Trigger Property="IsEnabled" Value="false">
<Setter Property="Background" Value="{DynamicResource Vertical_Gradient}" TargetName="Border"/>
<Setter Property="BorderBrush" Value="{DynamicResource DisabledBorderBrush}" TargetName="Border"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>