Abstract:Previous studies show that the arid and semi arid regions of North China serve as one of the principal sources of tropospheric dusts. The po ssible impacts of the aerosol concentration upon the formation and de velopment of mixed clouds in the condition of different dry atmosphere was discu ssed based on the modeling simulation. The factorial analysis method was used to identify impacts of the major and minor factors. The evidence suggests that (1) increase in sand aerosol s would lead to reducing precipitation, suppressing hail particle genesis, prolonging the existence of clouds and altering their space structure and micro scop ic features; (2) factorial analysis shows that in the arid and semi arid climat e the accumulated rainfall from mixed clouds is more sensitive to the change in th e number concentration of aerosols than to that in atmosphere moisture; (3) the a ugmentation of the number concentration would reduce accumulated precipitation; (4) increase of atmospheric humidity would be responsible for more accumulated ra infall. The presented results can be employed to account for the observational f act of the reduced number of hailfall days during a dry period of North China.