Based on the Hu Zhijin and Liu Qijun's cloud physics scheme, a new towmoment m icrophysical scheme is developed and incorporated in the GRAPES model.Using the mode which contains the new cloud physics scheme, a mountainous area cloud and precipitation process in the Qilian Mountain region is simulated. The microstruc ture of mountainous area cloud is studied and a numerical simulation on cloud se eding is conducted. The main analysis results are as follows: (1) The GRAPES mod el with twomoment scheme is able to reveal the distribution of precipitation, intensity and cloud field; (2) The new scheme can give reasonable microstructure of cloud system in the Qilian Mountain region and indicate its so me characteristics; (3) The artificial ice crystals seeding can lead to the increasing of precipitation, and the distribut ion of rain enhancement in the initial stage of cloud is wider than that in the development stage of cloud; (4) Dynamical structure of the cloud has some change s after seeding.