diff --git a/Spine/README.md b/Spine/README.md
index f7899bd..fde2add 100644
--- a/Spine/README.md
+++ b/Spine/README.md
@@ -1,3 +1,83 @@
 # Spine
 
-这个库封装了与 Spine 有关的底层功能.
+这个库封装了与 Spine 有关的底层功能, 下图给出主要关系.
+
+```mermaid
+classDiagram
+direction TB
+
+namespace Spine.SpineWrappers {
+    class ISkeleton { <<Interface>> }
+    class IAnimationState { <<Interface>> }
+    class ISpineObjectData { <<Interface>> }
+    class SpineObjectData { 
+        <<Abstract>> 
+        +CreateSkeleton() ISkeleton
+        +CreateAnimationState() IAnimationState
+    }
+}
+
+namespace Spine.Implementations.SpineWrappers.V38 {
+    class Skeleton38
+    class AnimationState38
+    class SpineObjectData38
+}
+
+namespace Spine {
+    class SpineObject {
+        +ISpineObjectData Data
+        +ISkeleton Skeleton
+        +IAnimationState AnimationState
+        +SpineObject(skelPath, atlasPath = null, version = null)
+    }
+}
+
+ISpineObjectData <|.. SpineObjectData
+
+Skeleton38 <.. SpineObjectData38
+AnimationState38 <.. SpineObjectData38
+
+ISkeleton <|.. Skeleton38
+IAnimationState <|.. AnimationState38
+SpineObjectData <|-- SpineObjectData38
+
+SpineObjectData38 <.. SpineObject
+
+```
+
+```mermaid
+classDiagram
+direction LR
+
+namespace Spine.Exporters {
+    class BaseExporter {
+         <<Abstract>>
+         +Export(output, params spines)
+    }
+
+    class VideoExporter {
+        <<Abstract>>
+        +Export(output, ct, params spines)
+    }
+
+    class FrameExporter
+    class FrameSequenceExporter
+    class FFmpegVideoExporter
+    class CustomFFmpegExporter
+}
+
+BaseExporter <|-- FrameExporter
+BaseExporter <|-- VideoExporter
+VideoExporter <|-- FrameSequenceExporter
+VideoExporter <|-- FFmpegVideoExporter
+VideoExporter <|-- CustomFFmpegExporter
+
+```
+
+## 如何扩展渲染支持的版本
+
+在命名空间 `Spine.Implementations.SpineWrappers` 下, 增加扩展版本的子命名空间, 例如 `V38`.
+
+随后实现 `SpineObjectData38`, 并继承自 `Spine.SpineWrappers.SpineObjectData`.
+
+并在实现类上使用特性注解 `[SpineImplementation(3, 8)]`.