The Resistance to the powdery mildew disease of 38 Pumpkin inbred-lines was estimated under natural circumstance.The results showed that remarkable difference was existed among the different pumpkin inbred lines.There were no immune types.There were 3 highly disease-resistance and 3 disease-resistant types,which occupied 7.89%.There were 11 middle disease-resistant types,which occupied 28.95%.There were 21 disease-susceptible types,which occupied 55.26%.Remarkable difference is existed among the hybrid combinations.