diff --git a/src/main/java/org/ntlab/citrusserver/repositories/TodoManager.java b/src/main/java/org/ntlab/citrusserver/repositories/TodoManager.java
index 4251341..6b48638 100644
--- a/src/main/java/org/ntlab/citrusserver/repositories/TodoManager.java
+++ b/src/main/java/org/ntlab/citrusserver/repositories/TodoManager.java
@@ -340,4 +340,14 @@
         int day = Integer.parseInt(yearMonthDays[2]);
         return setCheck(accountId, bookId, year, month, day, todoId, check);
     }
+
+    public void deleteAllTodosByBookId(String accountId, int bookId){
+        if(todos.containsKey(accountId)){
+            todos.get(accountId).remove(bookId);
+        }
+    }
+    public void deleteAllTodosByAccountId(String accountId){
+        todos.remove(accountId);
+    }
+
 }