Abstract: This study investigated the applicability of the WRF model in complex topographic conditions by modeling a weather incident that occurred in the west Yunnan region on July 13, 2014, using the WRF model and GSI assimilation system. The results showed that the location of the precipitation belt could be predicted by both the control model and assimilation model, although the intensity predicted by the control model was a little larger. The intensity of precipitation predicted by the assimilation model was somewhat weaker and the location of precipitation moved southward. In comparison to the results from TRMM, the precipitation predicted by the control model and assimilation model started late and had a longer duration. The precipitation region predicted by the control model was similar to the results from TRMM, while that predicted by the assimilation model was a little westward. In combining with the assimilated sounding data, the model significantly decreased the 24h-accumulated rainfall and RMSD of each site. The 1.0-h rainfall at each site simulated by the control model was larger, while the 1.0-h rainfall of each site simulated by the assimilation model was relatively small. This suggests that the assimilation model had the ability to predict single-peak precipitation. The simulation results for both the control and assimilation models for the area with multi-peak rain, and no or weak rain, had large errors. The WRF model has the ability to simulate precipitation incidents in complex terrain in the West Yunnan region. Coupling the model with GSI, it could adjust the distribution of each variable of the mode inputfield to influence the model simulation performance, however, the overall simulation results need to be further improved.