diff --git a/Sanchime.Functional/Core/Products/ICategory.cs b/Sanchime.Functional/Core/Products/ICategory.cs
new file mode 100644
index 0000000..63915e0
--- /dev/null
+++ b/Sanchime.Functional/Core/Products/ICategory.cs
@@ -0,0 +1,6 @@
+namespace Sanchime.Functional.Core.Products;
+
+public interface ICategory
+{
+    
+}
diff --git a/Sanchime.Functional/Core/Products/IFunctor.cs b/Sanchime.Functional/Core/Products/IFunctor.cs
new file mode 100644
index 0000000..1b81561
--- /dev/null
+++ b/Sanchime.Functional/Core/Products/IFunctor.cs
@@ -0,0 +1,11 @@
+namespace Sanchime.Functional.Core.Products;
+
+/// <summary>
+/// 函子
+/// 同一范畴内不同对象之间的映射
+/// </summary>
+/// <typeparam name="TCategory"></typeparam>
+public interface IFunctor<TCategory> : ICategory
+{
+    IFunctor<TResult> Map<TResult>(Func<TCategory, IFunctor<TResult>> mapping);
+}