Abstract: OBJECTIVE To establish the quality control system of pre-admixture mode by using the key operations which have influences on drugs admixture by pre-admixture mode after optimization as the key indexs in quality control. METHODS The key operations which had influences on drugs admixture by pre-admixture mode had been found, which including accuracy, the way of checking finished infusion and the residue produced by pump. Through the optimization of the way of draining bubbles, calibration and pumping volume to guarantee the accuracy of pump and finished infusion. The way of checking finished infusion was improved. The residue produced by pump was detected to judge whither it met the standard or not. RESULTS The key operations having influences on drugs admixture by pre-admixture mode were improved. Using these key operations as key indexes to establish the quality control system, and other indexes, including aseptic admixture operation, storage condition of stock solution and standardization of all operations in pre-admixture mode were normalized. CONCLUSION The key indexes of quality control system have been got in the process of the optimization, and the quality control system of pre-admixture mode will established on this basis in pharmacy intravenous admixture services.