The White Paper of Diaoyu Dao, an Inherent Territory of China implies a lot of principles of international law, including that China preempted the territorial sovereignty over Diaoyu Dao, the principle that a treaty shall be abided by the contracting parties safeguards China`s territorial sovereignty over Diaoyu Dao, the cession and prescription can't support Japan`s sovereignty claim over Diaoyu Dao and the principle that the illegal behavior does not produce a legal right refuses to Japan`s territorial claim over Diaoyu Dao and etc. The legal facts revealed by the White Paper also clearly show that Japan`s claim to the territorial sovereignty over Diaoyu Dao through preempting a non-owner land cannot be established and its actual control is not up to the standard of an effective control required in international law. China should actively use the legal facts revealed in the White Paper and the principles of international law implied in it to refute Japan`s sovereignty claims over Diaoyu Dao and make the international community know well the truth of the dispute over Diaoyu Dao between China and Japan. At the same time, China should continue to strengthen the actual control over Diaoyu Dao and its subsidiary waters to enrich the basis of international law for the dispute`s legal solution at last when the time comes in the future.