Abstract: Potential model has been widely applied in measurement of spatial accessibility to health care services, and such approach can be used to evaluate the fairness of the distribution of health care facilities. The existing formulas had integrated three main factors including the service capacity of health care facilities, the population in demands and travel impedance between population location and provider location. It is worth mentioned that a vital factor that the impact from the health care facilities with different levels (different grades and scales)to the selections of residents with some approximate service demands was considered in the study, and such factor was integrated into the existing formulas to improve the comprehensiveness and accuracy of potential model when measuring spatial accessibility. Based on the data of Rudong county in Jiangsu Province by the end of 2007 which refer to hospitals, residents, traffic network and so on, the improved potential model was applied to assess the variation of spatial accessibility to hospitals in Rudong county as positive area. Through the study, the following conclusions were reached:Based on the proper travel friction coefficients, the improved potential model proposed can be more reasonable and comprehensive to measure spatial accessibility to health care facilities, and can be accurate to reveal the health care resource quantity which any population location can access in the context of competition by those demanders due to travel impedance within certain threshold travel time, furthermore, health professional shortage areas of positive area can be defined effectively with certain standards developed by public health management sector, which can support the basis for decision-making of health service planning. On the whole, such approach was explored for spatial accessibility to health care services and the designation of health professional shortage areas by covering more factors closer to reality in this research.