Since specific provisions on human rights issues are rarely seen in current international investmentagreements which set a considerably high protection standard for investors, the conflict and contradiction betweenprotection for the human rights of residents of host states and protection for the property rights of investors. Theinvestor-state arbitration unveiled those potential conflicts. In practice, investment arbitration tribunals are zealousfor protecting investors’property rights, and indifferent to protecting economic and social human rights of residentsof host states. The source of the conflict is the failure to clarify the theoretical connotation of“self-containment of international investment law” and “positioning of arbitral tribunal”. In order to strike a balance betweenprotecting human rights of residents of host states and protecting property rights of investors, the international investment law must evolve in respect of substance and procedure.