The preliminary ruling by the South China Sea arbitration case gives a number of explanations on the UN Convention, which are in favor of the Philippines, especially the Arbitral Tribunal made preliminary ruling over the appeal demands unclearly excluded by both the UN Convention and the Chinese Statement and established jurisdiction, but made no preliminary ruling regarding the clearly excluded appeal demands, and established them directly into the substantive consideration, and that phenomenon has strong subjective approach. The preliminary ruling is the joint processing of legal abuse by the Arbitral Tribunal and the Philippine side, so the hope on the Arbitration case should not be placed on the inside of the Arbitral Tribunal but on the outside of the Arbitral Tribunal. The matters established under the jurisdiction by the preliminary ruling is not related to the core matter of the South China Sea disputes, bears a little practical impact on the Chinese side. However, the Arbitral Tribunal may take the opportunity to review the “historic rights” such as those excluded in order to give covert support to the Philippines and other islands-claiming countries so as to affect the overall situation of the case. In view of the defects in designing of Annex Ⅶ of the UN Convention and the possible abuse of the system, the Chinese side should get prepared. Only on the basis of internationally accepted practice and the UN Convention, should China make rational and convincing arguments, recognize the preliminary ruling is the result of legal abuse, and safeguard national rights and interest with the international law and prevent the civil abuse actions. The preliminary ruling by the South China Sea arbitration case gives a number of explanations on the UN Convention, which are in favor of the Philippines, especially the Arbitral Tribunal made preliminary ruling over the appeal demands unclearly excluded by both the UN Convention and the Chinese Statement and established jurisdiction, but made no preliminary ruling regarding the clearly excluded appeal demands, and established that directly into the substantive consideration, and that phenomenon has strong subjective approach. The preliminary ruling is the joint processing of legal abuse by the Arbitral Tribunal and the Philippine side, so the hope on the Arbitration case should not be placed on the inside of the Arbitral Tribunal but on the outside of the Arbitral Tribunal. The matters establish under the jurisdiction by the preliminary ruling is not related to the core matter of the South China Sea disputes, bears a little practical impact on the Chinese side. However, the Arbitral Tribunal may take the opportunity to review the “historic rights ” such as those excluded in order to give covert support to the Philippines and other islands-claiming countries so as to affect the overall situation of the case. In view of the defects in designing of Annex Ⅶ of the UN Convention and the possible abuse of the system, the Chinese side should get prepared. Only on the basis of internationally accepted practice and the UN Convention, should China make rational and convincing arguments, recognize the preliminary ruling is the result of legal abuse, and safeguard national rights and interest with the international law and prevent the civil abuse actions.