Abstract: Weather Research and Forecasting(WRF) model coupled with Morrison’s double-moment bulk microphysical scheme is used to simulate the climate effect of increasing aerosol in three mega city agglomeration. The results show that while increasing concentrations of aerosol particles, sensitive and latent heat at land surface decrease over most eastern China area, at the same time, temperature at 2 m decreases as well in most of east China. As far as concentrations of aerosol particles increased, the response relationship between concentration of aerosol particles and precipitation is complex, lacking identical regularity,but precipitation decreasesover most of eastern China area. The increase of aerosol particles concentration lead to atmosphericwater vapor transportation, which is the main reason of aerosol indirect effect to change east Asian summer monsoon precipitation. On the other hand, vertical circulation change is the subsidiary factor to lead the east Asian summer monsoon precipitation change. Over all, higher concentration of aerosol particles in different areas lead to precipitation reduced, atmosphericwater vapor and temperature of lower layer atmosphere decreased over most of eastern China, and it reveals a dry and cold climate trends.