| In recent years, with liberalization, facilitation and integration development of international investment, international direct investment expands rapidly, Disputes about international investments are increasing between foreign investors and host country. Such disputes are inclined to change from political features to managerial ones. "Umbrella clauses" founded by developed countries are dedicated protect investors interests, application of which are evolved from comprehensively unconditional, restrictive, till relatively restrictive appliance. At the beginning of creation of such clause, it only emphasizes all-direction protection to investors, later on, is turns to seek a balance between foreign investors and host countries interests, "umbrella" clause offer the investor a good method to solve investment disputes, when investor's behavior is not only against of contract between investor and host but the agreement and treaty. International arbitration finds it difficult to apply the "umbrella" clause when they are dealing with the relations between lawsuits against contract and treaty, they even can not define the arbitration jurisdiction. At present, the international arbitration does not form a unified opinion in "umbrella" clause practice. Individual case says the arbitration practice favors foreign investors more, mainly because of the improper expanding "umbrella" clause definition in the investment treaty, which pose a serious violation of sovereignty of host countries. Based on the analysis of the relationship between "umbrella" clause and some other clauses of investment treaty, this thesis is going to put forward some suggestions to perfect the application of "umbrella" clause, in order for it to play a better role in investment treaty. According to the current situation and future development tendency of investment treaty establishment in china, this thesis is going to conclude more suggestions for on whether and how to establish "umbrella" clause in investment treaty when china is regarded as either capital importer or exporter, so as to maximize china's interests. |