Abstract: Acid rain pollution is a serious environmental problem in the world, especially for the phosphorus deficiency in paddy soil. The present study aims to investigate the impact of simulated acid rain upon the dynamics of soil phosphorus (total phosphorus, available phosphorus, soil microbial biomass phosphorus (SMB-P) and phosphatees activity) and soil pH in paddy soil. Results showed that soil pH and total phosphorus in the paddy soil did not significantly changed with the acid rain leaching at pH levels of 3.5, 4.5, 5.5 over a 40-day simulation period, indicating a buffering capacity of paddy soil to acid rain. However, the available phosphorus content changed significantly, which tended to decline. Of the three levels of the simulated acid rain, the available phosphorus content was the lowest when the pH was 5.5. As the increase of acid rain acidity, both SMB-P and phosphatees activity tended to increase and then to decrease. Our study indicated that simulated acid rain with pH≥4.5 and pH>3.5 could help to increase the content of SMB-P and phosphatees activity, respectively. But the high-strength acid rain gradually restricted the population and activities of soil microbes.