Abstract: This paper studied the pollutants released from swine manure on open ground under leaching of acid rain, analysed environmental harm of the release. Simulation tests were carried out under Guangdong acid rain condition, using pH 3.60, 4.80 and 5.60 of the leaching solution, showering for 24 days for fresh pig manure.Experiment results showed that heavy metal of Cu, Zn, As,ammonia, total phosphorus, and COD were formd in pollutamts,and their time-concentration curves were plotted. The results show that after acid rain leaching the pH of swine feces lower than that of fresh swine manure,and during the 24 days the concentration of Cu, Zn and As in leached swine feces showed decline trend, the leaching rate of heavy metal in the treatment of pH4.8 was faster than that in treatment of pH 3.6 and 5.6; COD and ammonia leaching rates were fast at start, then it slowed down. After acid rain leaching all concentrations of copper, arsenic, COD,total phosphorus, and ammonia in swine feces were over the relevant environmental standards. So it is necessary to take measures to prevent fresh swine manure from leaching.