diff --git a/app/src/main/java/net/micode/notes/gtask/data/MetaData.java b/app/src/main/java/net/micode/notes/gtask/data/MetaData.java
index fc75821..2fb1601 100644
--- a/app/src/main/java/net/micode/notes/gtask/data/MetaData.java
+++ b/app/src/main/java/net/micode/notes/gtask/data/MetaData.java
@@ -27,7 +27,7 @@ import org.json.JSONObject;
 
 public class MetaData extends Task {
     /*
-     * 功能：得到类的简写名称存入字符串TAG中
+     * 功能：得到类的简称存入字符串TAG中
      * 过程：调用getSimpleName ()函数
      */
     private final static String TAG = MetaData.class.getSimpleName();
diff --git a/app/src/main/java/net/micode/notes/gtask/data/Node.java b/app/src/main/java/net/micode/notes/gtask/data/Node.java
index 63950e0..31f5be8 100644
--- a/app/src/main/java/net/micode/notes/gtask/data/Node.java
+++ b/app/src/main/java/net/micode/notes/gtask/data/Node.java
@@ -20,6 +20,9 @@ import android.database.Cursor;
 
 import org.json.JSONObject;
 
+/**
+ * 定义了一些有关同步操作的常量，Node为同步操作的基础类
+ */
 public abstract class Node {
     public static final int SYNC_ACTION_NONE = 0;
 
diff --git a/app/src/main/java/net/micode/notes/gtask/data/SqlData.java b/app/src/main/java/net/micode/notes/gtask/data/SqlData.java
index 211eba2..72871ea 100644
--- a/app/src/main/java/net/micode/notes/gtask/data/SqlData.java
+++ b/app/src/main/java/net/micode/notes/gtask/data/SqlData.java
@@ -34,7 +34,9 @@ import net.micode.notes.gtask.exception.ActionFailureException;
 import org.json.JSONException;
 import org.json.JSONObject;
 
-
+/**
+ * 功能：支持最底层的数据库操作，在逻辑关系上是Sqldata是Node类的子集
+ */
 public class SqlData {
     private static final String TAG = SqlData.class.getSimpleName();
 
diff --git a/app/src/main/java/net/micode/notes/gtask/data/SqlNote.java b/app/src/main/java/net/micode/notes/gtask/data/SqlNote.java
index 3ff745e..202b72a 100644
--- a/app/src/main/java/net/micode/notes/gtask/data/SqlNote.java
+++ b/app/src/main/java/net/micode/notes/gtask/data/SqlNote.java
@@ -37,7 +37,9 @@ import org.json.JSONObject;
 
 import java.util.ArrayList;
 
-
+/**
+ * 功能：支持最底层的数据库操作，从SqlData中具体出的便签类数据，是真正意义上的便签数据
+ */
 public class SqlNote {
     private static final String TAG = SqlNote.class.getSimpleName();
 
diff --git a/app/src/main/java/net/micode/notes/gtask/data/Task.java b/app/src/main/java/net/micode/notes/gtask/data/Task.java
index 6a19454..6207612 100644
--- a/app/src/main/java/net/micode/notes/gtask/data/Task.java
+++ b/app/src/main/java/net/micode/notes/gtask/data/Task.java
@@ -31,7 +31,9 @@ import org.json.JSONArray;
 import org.json.JSONException;
 import org.json.JSONObject;
 
-
+/**
+ * 与Node是父子关系，继承了原有的属性和方法，并在此基础上定义更加具体的功能
+ */
 public class Task extends Node {
     private static final String TAG = Task.class.getSimpleName();
 
diff --git a/app/src/main/java/net/micode/notes/gtask/data/TaskList.java b/app/src/main/java/net/micode/notes/gtask/data/TaskList.java
index 4ea21c5..0f5dbe9 100644
--- a/app/src/main/java/net/micode/notes/gtask/data/TaskList.java
+++ b/app/src/main/java/net/micode/notes/gtask/data/TaskList.java
@@ -29,12 +29,16 @@ import org.json.JSONObject;
 
 import java.util.ArrayList;
 
-
+/**
+ * 继承自Node，拓展了一些有关Task列表的基础操作
+ */
 public class TaskList extends Node {
     private static final String TAG = TaskList.class.getSimpleName();
 
     private int mIndex;
-
+    /*
+     * 创建一个以Task为基本元素的ArrayList
+     */
     private ArrayList<Task> mChildren;
 
     public TaskList() {