Objectives To estimate the elasticity of demand price elasticity and demand income of urban and rural residents’ self-purchase drug use and expenditure, and to analyze the sensitivity of self-purchase drug use and expenditure to the price change of drug purchase, resident income and medical institutions. Methods The data were derived from the fifth health service survey in Heilongjiang province in 2013. The Probit model was used to obtain the partial regression coefficients of the control variables in the regression model, and the demand elasticity of the self-purchase drug use was further measured by the partial regression coefficients, and the demand elasticity of self-purchase expenditure was obtained by the logarithmic regression model. Results A total of 5 289 households (14 431 persons) were included. The demand for self-purchase drug use of Heilongjiang province was 0.374 (P=0.000), the cross-price elasticity of self-purchase drug utilization and service was –0.184 (P=0.000), and the income elasticity was 0.083 (P=0.172). Since the price elasticity of the self-purchase drug expenditure was 0.675 (P=0.000), the income elasticity was 0.144 (P=0.069). Conclusions The use of self-purchased drugs in Heilongjiang province lacks price elasticity and is a necessity. There is a complementary relationship between the use of self-purchase drugs and medical institutions.