Chinese CPA profession, established in 1980, has only just 20 years, and the US CPA profession development for many years, the US has 120 certified public accountants industry in the world is the forefront, its all aspects of Therefore, based on the development of industry and certified public accountants registered accountants development and economic environment, the organization and the scope of business and CPA profession supervising mode, and discusses the development in the CPA firm with economic environment, organization form and scope of business in China, and combining the CPA professional supervision and the mode of our profession supervising the author puts forward three S Hope to the healthy development of the CPA professional Responsibility accounting system of securities market construction condition, will decide card is investor reasonable degree of maintenance, current registered accountants in issuing certificates and standardize the market in the United States, and need of securities market development is closely related with the CPA should bear the legal responsibility for securities investors in China, especially the legal responsibility of This paper briefly sino-american for securities investors CPA legal responsibility system, and the relevant provisions of the differences between us, through comparison study of securities investor legal system of our country, the useful experience of securities system are