OBJECTIVE： To provide reference for evaluating the new round of essential medicine bidding and purchase policy in China， ensuring the stability of essential medicine supply and improving national essential medicine system. METHODS： Based on the theoretical analysis， taking Shanghai and Yunan province as sample， the questionnaire was designed to investigate the difficulty to implement essential drug purchase policy in essential medicine supply system， and the bidding situation evaluation of production enterprises by both sides of local drug bidding among staff in production enterprises， circulation enterprises， primary health care institutions and other institutions. The types of influential factors for the implementation of essential medicine purchase policy were determined finally. Factor analysis method was used to screen the key influential factors. RESULTS & CONCLUSIONS： Four common factors had a great influence on the implementation of essential medicine policy in China. The impact of the large to small is the rationality of the tender procurement program， the standardization of pharmaceutical production， the stability of demand for drug use and macroeconomic policy regulation and protection. It is suggested to further improve the drug recruitment system， select the products that have quality assurance and production specifications， and fully meet the diverse needs of the market， while provide relatively stable usage information for manufacturers. If necessary， “drug purchase with target quantity” of Shanghai model can be forced to carry out by policy so as to ensure that the interests of all parties in the pharmaceutical supply chain are treated fairly.