Abstract: OBJECTIVE To improve the mass balance of hospital preparations, and to ensure the quality of hospital preparation by carrying out quality control circle(QCC) activity. METHODS According to the ten steps of QCC, the mass balance dates of 76 batches of hospital preparations in 2014 were collected, the major factors of low mass balance of preparations were analyzed, corresponding countermeasures were formulated and evaluated. RESULTS Via the QCC activity, the mass balance of hospital preparation was increased from 96.52% to 99.54%, and the ability of the circle member to solve problem, the methods of QCC, the sense of responsibility, cohesion and other intangible results had been improved. CONCLUSION Through the implementation of QCC activity, the mass balance and the management level of hospital preparations are improved effectively.