Analysis and identification on seeding opportunity for enhancing rainf all in a convectional precipitation case occurred in northwestern Hubei, a mount ainous area, are introduced. Firstly, based on a fully elastic threedimensiona l and dualparameter cumulus cloud numerical model, a series of sensitive model ing tests on seeding AgI agent in a variety of time is conducted to analyze how various seeding time affects the result of precipitation enhancement and its pre cipitation physical mechanism. It is concluded that the appropriate seeding oppo rtunity is at the earlyperiod when a convective cloud is developing after its ori ginal formation. According to the results of simulation analysis in this case an d based on radar data, the method of detecting appropriate seeding opportunity i s discussed by analyzing forming and developing characteristics of convective ce ll echoes in the entire precipitation process.