Dust storms that impact China mostly happen in spring, seldom in summer. The dust aerosol model (GRAPESDAM) is applied to simulate a group of dust severe storms occurred in Hexi Corridor in July 2005. By means of the case simulation and analysis, the feasibility of summer severe dust storm predictions is discussed. The simulation shows that the model can simulate successfully the dust storms, including the surface wind, the spreading area, and the movement of the dust storms. For summer clustering severe dust storms, in condition of exact numerical prediction of the synoptic pattern and meteorological fields, the dust aerosol model is able to make meaningful prediction of this kind of dust storms.