The conduct of supporting legislation of regional national autonomy in Guangxi is not only to improve the Chinese system of natiional laws and regulations,but also to better implement the Law of the People’s Republic of China on Regional National Autonomy.There are some deficiencies in the supporting legislation of regional national autonomy in Guangxi,such as incomplete existing supporting legislation,insufficient contents concerning ethnic legislation in local laws and regulations and lack of important supporting legislation at the level of autonomous region.This paper puts forward some proposals to perfect the supporting legislation of regional national autonomy in Guangxi:1,to speed up the local supporting legislation with the leading of central-level supporting legislation;2,to improve the quality and quantity of supporting legislation;3,to formulate local ethnic regulations to make up for the lack of separate regulations at the level of autonomous region;4,to promote the formulation and implementation of important supporting legislation at the level of autonomous region.