Being vast in system and numerous in quantity,China's administrative organs have applied a large number of international treaties in the practice of administrative law enforcement,which has legitimacy and le-gality. The legitimacy includes the need to strengthen the construction of the foreign-related legal system in the new era,the need to implement the rule of law in a comprehensive manner,and the inevitable requirement for China's administrative organs to actively participate in global governance. The legal basis for the application of treaties by China' s administrative organs includes the principle that treaties must be observed,that China' s ad-ministrative organs are important entities responsible for the domestic application of treaties,and that the norms involving administrative management behavior in international treaties concluded by China constitute an impor-tant source of administrative law. In addition,the application of treaties by China' s administrative organs has a relatively sufficient legal basis in terms of laws,administrative regulations and administrative rules.