Abstract: Based on the provincial panel data of 7 provinces in China from 2009 to 2017,this paper employs panel fixed effect model and panel threshold model to investigate the differences in the relationship between social medical insurance and commercial health insurance on different income levels.The results of the study show that the development of social medical insurance has promoted the development of commercial health insurance in general,but the relationship between the two is non-linear complementary and promotive,and this promotive effect is growing with the increase of residents’income level.However,when the per capita income of residents is lower,this promotive effect is not significant.Therefore,vertically,with the development of China’s economy,the improvement of social medical insurance will comprehensively promote the development of commercial health insurance.Horizontally,there is a big income gap between urban and rural residents in China;the focus of medical security system should have some differences towards rural and urban residents.The commercial insurance companies should design commercial health insurance products for people at different income levels from both macro and micro perspectives to meet people’s diversified medical security needs at different economic stages,which will also be connected with the basic medical insurance.

Key words: commercial health insurance, social medical insurance, panel threshold model