Abstract: The Immunity Right of the State Head is a controversial issue in both practice and theory. This paper, focusing on the international law principle of immunity right, explains theory issues and practice issues comprehensively from history origin, theoretical foundation, doctrine, international convention, judgment of the International Court of Justice and practice of U.S and U.K, and draws a conclusion:international law principe which limits the immunity of the state head (particularly right of criminal immunity) has not been established yet; depriving of the immunity right of the state head arbitrarily will damage the sovereignty of state.