diff --git a/update_log.txt b/update_log.txt
deleted file mode 100644
index e6e10f4f6a76cb6ac554b3f9082956a9ed7c0ea2..0000000000000000000000000000000000000000
--- a/update_log.txt
+++ /dev/null
@@ -1,35 +0,0 @@
-2021/4/15
-////////////////////////////////////////////////////////
-
-New variables
-************************************************
-In Class Simulation:
-    private static double ACTIVITY_UNIT_PRICE;
-    private static double MARKUP_PERCENTAGE;
-
-In Class MailPool:
-    In private Class Item:
-        double charge;
-        boolean isNewItem = true;
-************************************************
-
-New methods
-************************************************
-In Class MailPool:
-    public double calculateCharge;
-    public void setItemCharge;
-    public void getItemInfo;(This method is not a part of assignment, it will be removed)
-    public boolean isNewItem;
-    public int getItemDestination;
-    public int getPoolSize;
-    public void sortPriorityMailItems;
-************************************************
-
-New codes
-************************************************
-In Class Simulation:
-    from line 81 to line 95
-    from line 119 to line 121
-    from line 156 to line 161
-************************************************
-////////////////////////////////////////////////////////
\ No newline at end of file