Cold frontal precipitation case occurring during 31 Mar－1 Apr 2004 in South China is studied with CAMS mesoscale cloud resolving model. The simulation results are verified with observational surface rainfall, satellite and radar data. The occurring time, location, shape and orientation of simulated cloud bands and their evolution are consistent with the satellite observation. The distribution of simulated radar echoes is in agreement with radar observation. The southwest－northeast band echoes mainly occurred at surface frontal line and post-frontal part. The difference of individual echoes in different parts of the cold front is great. The distribution and amount of simulated surface rainfall during the main precipitating period coincide with the observations. The mesoscale southwest－northeast rain band moves southeasterly with cold front moving. There are four strong precipitating centers in the rain band, whose lifetimes are beyond 3 hours, and move mostly eastward, which agrees with the moving of radar echoes. The vertical motion of cold frontal clouds is deep and corresponding to the cloud area. The clouds appear in the areas of convergence, positive vorticity in the lower level, divergence in the upper level, and higher equivalent potential temperature. Near the surface front line, the updraft velocity is great, and the mass content of cloud water is great, then the processes of ice particles riming and collection of cloud droplets by raindrops are the main microphysical processes. However, in the wide rain band areas, updrafts only lie in upper layers, downdrafts are in lower layers, and there are mainly supercooled cloud water, graupels and snow crystals. Snow crystals are the main source term for graupel growing, precipitation is mainly formed by graupels melting, cold rain process is more important.