Abstract: The arbitration tribunal constituted under Annex VII of the UNCLOS published the award between Mauritius and Britain on March 18，2015．The arbitration under Annex VII of the UNCLOS have compulsive character，but its scope shall be subject to limitations．The existence of disputes is the precondition of the compulsory arbitration and it must be legal disputes．In deciding whether the disputes in question belong to those of of interpretation or application of the UNCLOS，it is necessary to clarify the difference between the apparent disputes and the material disputes as well as that between the overall disputes and partial disputes．Sovereignty affect the scope of compulsory arbitration deeply and it will play different roles in different cases．The request of Philippines in the arbitration between Philippines and China falls out of the scope of the compulsory arbitration which was constituted under Annex VII of the UNCLOS and should be rejected．

Key words: compulsory arbitration; UNCLOS; sovereignty