Abstract: In order to investigate the mechanism of rainfall on heavy metal accumulation in tobacco leaves, a series of parameters such as rainfall frequency, precipitation and pH of rainwater were studied via rainfall simulation experiments in fields and greenhouses. The results showed that washing with deionized water decreased the heavy metal accumulation in tobacco leaves collected from fields at different stages, the average reduction rates of As, Pb and Ni were 18.19%, 16.67% and 15.62%, respectively. The simulated rainfall experiments indicated that the heavy metal concentration and pH of rainwater and precipitation influenced the heavy metal accumulation in tobacco leaves. Taking the groundwater containing lower heavy metals as simulated rainwater, the results of field experiments indicated that rainfall frequency slightly affected the heavy metal accumulation in tobacco leaves at equal precipitation. At equal rainfall frequency, the accumulation of Cr, Ni, As and Pb in tobacco leaves decreased with the increase of precipitation. The results of rainfall simulation experiments in greenhouses suggested that when the Pb concentration in simulated rainwater was 10.0 μg/L, the pH of rainwater and precipitation significantly affected the Pb accumulation in tobacco leaves, and the Pb accumulation in tobacco leaves and stalks increased at lower pH and higher precipitation.