diff --git a/src/main/scala/com/github/shadowsocks/database/DBHelper.scala b/src/main/scala/com/github/shadowsocks/database/DBHelper.scala
index d2ed5a4c..627d6b48 100644
--- a/src/main/scala/com/github/shadowsocks/database/DBHelper.scala
+++ b/src/main/scala/com/github/shadowsocks/database/DBHelper.scala
@@ -51,7 +51,7 @@ object DBHelper {
 }
 
 class DBHelper(val context: Context)
-  extends OrmLiteSqliteOpenHelper(context, DBHelper.PROFILE, null, 12) {
+  extends OrmLiteSqliteOpenHelper(context, DBHelper.PROFILE, null, 13) {
 
   lazy val profileDao: Dao[Profile, Int] = getDao(classOf[Profile])
 
@@ -89,6 +89,11 @@ class DBHelper(val context: Context)
             " ipv6, individual FROM `tmp`;")
           profileDao.executeRawNoArgs("DROP TABLE `tmp`;")
         }
+        if (oldVersion < 13) {
+          profileDao.executeRawNoArgs("ALTER TABLE `profile` ADD COLUMN tx LONG;")
+          profileDao.executeRawNoArgs("ALTER TABLE `profile` ADD COLUMN rx LONG;")
+          profileDao.executeRawNoArgs("ALTER TABLE `profile` ADD COLUMN date DATE;")
+        }
       }
     }
   }
diff --git a/src/main/scala/com/github/shadowsocks/database/Profile.scala b/src/main/scala/com/github/shadowsocks/database/Profile.scala
index 8be48264..66744357 100644
--- a/src/main/scala/com/github/shadowsocks/database/Profile.scala
+++ b/src/main/scala/com/github/shadowsocks/database/Profile.scala
@@ -83,4 +83,13 @@ class Profile {
 
   @DatabaseField(dataType = DataType.LONG_STRING)
   var individual: String = ""
+
+  @DatabaseField
+  var tx: Long = 0
+
+  @DatabaseField
+  var rx: Long = 0
+
+  @DatabaseField
+  val date: java.util.Date = new java.util.Date()
 }
diff --git a/src/main/scala/com/github/shadowsocks/utils/TrafficMonitor.scala b/src/main/scala/com/github/shadowsocks/utils/TrafficMonitor.scala
new file mode 100644
index 00000000..eb715113
--- /dev/null
+++ b/src/main/scala/com/github/shadowsocks/utils/TrafficMonitor.scala
@@ -0,0 +1,83 @@
+package com.github.shadowsocks.utils
+
+import android.net.TrafficStats
+import android.os.Process
+import java.lang.{String, System}
+import java.util.Locale
+
+case class Traffic(tx: Long, rx: Long, timestamp: Long)
+
+object TrafficMonitor {
+  val uid = Process.myUid
+  var last: Traffic = getTraffic
+
+  // Kilo bytes per second
+  var txRate: Long = 0
+  var rxRate: Long = 0
+
+  // Kilo bytes for the current session
+  var txTotal: Long = 0
+  var rxTotal: Long = 0
+
+  def getTraffic(): Traffic = {
+    new Traffic(TrafficStats.getUidTxBytes(uid),
+      TrafficStats.getUidRxBytes(uid), System.currentTimeMillis())
+  }
+
+  def formatTraffic(n: Long): String {
+    if (n <= 1024) {
+      "%d KB".formatLocal(Locale.ENGLISH, n)
+    } else if (n > 1024) {
+      "%d MB".formatLocal(Locale.ENGLISH, n / 1024)
+    } else if (n > 1024 * 1024) {
+      "%d GB".formatLocal(Locale.ENGLISH, n / 1024 / 1024)
+    } else if (n > 1024 * 1024 * 1024) {
+      "%d TB".formatLocal(Locale.ENGLISH, n / 1024 / 1024 / 1024)
+    } else  {
+      ">1024 TB"
+    }
+  }
+
+  def updateTraffic() {
+    val now = getTraffic
+    txRate = ((now.tx - last.tx) / 1024 / (now.timestamp - last.timestamp))
+    rxRate = ((now.rx - last.rx) / 1024 / (now.timestamp - last.timestamp))
+    txTotal += (now.tx - last.tx) / 1024
+    rxTotal += (now.rx - last.rx) / 1024
+    last = now
+  }
+
+  def resetTraffic() {
+    txRate = 0
+    rxRate = 0
+    txTotal = 0
+    rxTotal = 0
+    last = getTraffic
+  }
+
+  def getTxTotal(): String = {
+    formatTraffic(txTotal)
+  }
+
+  def getRxTotal(): String = {
+    formatTraffic(rxTotal)
+  }
+
+  def getTotal(): String = {
+    formatTraffic(txTotal + rxTotal)
+  }
+
+  def getTxRate(): String = {
+    formatTraffic(txRate) + "/s"
+  }
+
+  def getTxRate(): String = {
+    formatTraffic(rxRate) + "/s"
+  }
+
+  def getRate(): String = {
+    formatTraffic(txRate + rxRate) + "/s"
+  }
+}
+
+class TrafficMonitor ()