It explores the incentive and constraint mechanism of stabilizing rural doctors staff under the background of the essential medicine system based on theprincipal-agenttheory.Through the analysis of theprincipal-agentrelationship in the village clinic after implementing essential medicine system,we discover that the implementation of essential medicine system in the village clinic has complicated principal-agent relationship.The information asymmetry and the goal incompatibilities may the most important reasons that affected the essential medicine system in village clinic.The government,as an important client should pay attention to play active role,take reasonable incentive and constraint measures,to arouse the enthusiasm of rural doctors,stabilize rural doctors staff,and assure the implementation about essential medicine system in the village clinic.

Objective To study the changes on drug costs and drug consumption structure before and after the implementation of the national essential medicine system( NEMS) in township hospitals in a city of Shandong province. Methods A total of 18 township hospitals were chosen through simple random sampling. The financial information and the information of the top fifty frequently used drugs in the 18 hospitals before and after the NEMS implementation were collected through quantitative survey and semi- structured interviews. Descriptive statistical analyses were applied to analyze the data. Results Compared with the condition before the NEMS implementation,the total expenses per capita of outpatient and inpatient after the implementation dropped by 40. 2% and 8. 2%,respectively; and drug expenses per capita of outpatients and inpatients dropped by 48. 5% and41. 2%,respectively. The structure of frequently used drugs also changed; in the 50 frequently used drugs,the proportions of the essential medicine and the traditional Chinese medicine increased by 23. 6% and 16. 3%,respectively; while the proportions of injection and antibacterial drug injection decreased by 7. 6% and 0. 9%,respectively. Conclusion The implementation of NEMS reduces the medical burden of the patients and promotes the rational use of drugs to some extent. But the relevant supporting policies still need to be perfected,the list of the national essential medicine should be adjusted,the essential medicine supply should be guaranteed,the rational use of essential medicine should be further improved,and financial compensation model should be reformed.