Based on the 2015 China Social Comprehensive Survey Data （CGSS 2015）， the binary logistic model was applied to study the influence factors of urban residents’ purchase of commercial medical insurance. The coverage rate of commercial medical insurance for urban residents in China was low， only 14.5% of urban residents have purchased commercial medical insurance. Whether residents buy commercial medical insurance or not was mainly influenced by their working status， education level and family income， among which the working status has the greatest influence.