With the 3D convective cloudmodel of CAMS,we simulate a convective cloud process in Qinghai in Autumn 2002,with emphases on dynamical andmicrophysical processes.Simulation results indicate that convective precipitation is almost all transformed bymelting of graupels,but in unseeded clouds,the ice crystals amount is such rare that it contributes little to graupel formation.After seeding in proper position and time,the formation and ramification of ice crystals are enhanced.Automatic transformation from ice crystals to grauple contributesmuch to graupel embryoes.Almost allmicrophysical processes in seeded clouds aremore active than those in unseeded clouds,and at the same time,the seeding changes the dynamical fields in the cloud in such a way that the inaction between dynamical andmicrophysical processes leads to precipitation enhancement.