Abstract: In international investment law,the key element of sustainable development reform is to balance the interests between host states and foreign investors,which stresses that the objective of protecting and encouraging investment should not affect host states' right to regulate public interests. In recent years,host states' right to regulate has achieved comprehensive development in both international investment agreements(ⅡAs)and international investment arbitration practice by means of limiting the definition of investment and investor,refining indirect expropriation standards, introducing the exceptions of prohibition on performance requirements and rectifying ISDS mechanism. In order to achieve friendly and sustainable reform,the most effective way is to make specialized clauses on the right to regulate and introduce proportional principles that ensure the orderly implementation of the right to regulate. For our country,while amending relevant provisions with own conditions,it is necessary to be an active participant in the ⅡAs reform of sustainable development so as to enhance international discourse power.