I am been trying to copy a apk from assets of another apk to /system. Here is what I have done,it was working in my previous app but not in this.I have added permission for wrtiting external storage. It is successfully copying to internal storage,not not to /system. Is there any way to directly copy to /system? copyStream("y.apk","/sdcard/x.apk"); Process mSuProcess; mSuProcess = Runtime.getRuntime().exec("su"); new DataOutputStream(mSuProcess.getOutputStream()).writeBytes("mount -o remount rw /system"); DataOutputStream mSuDataOutputStream = new DataOutputStream(mSuProcess.getOutputStream()); mSuDataOutputStream.writeBytes("cp /sdcard/x.apk /system/app/x.apk"); mSuDataOutputStream.writeBytes("exit\n");