diff --git a/README.md b/README.md
index e611181..0e6e764 100644
--- a/README.md
+++ b/README.md
@@ -45,6 +45,26 @@ Future task               :         des3, after des2, 5d
 Future task2               :         des4, after des3, 5d
 ```
 
+# Class diagram
+
+```mermaid
+classDiagram
+Class01 <|-- AveryLongClass : Cool
+Class03 *-- Class04
+Class05 o-- Class06
+Class07 .. Class08
+Class09 --> C2 : Where am i?
+Class09 --* C3
+Class09 --|> Class07
+Class07 : equals()
+Class07 : Object[] elementData
+Class01 : size()
+Class01 : int chimp
+Class01 : int gorilla
+Class08 <--> C2: Cool label
+```
+
+