Abstract: The interrelations of acid rain and soil ecosystem are analysed.Acid rain could change soil acidity, enhance soil toxicity, reduce soil active,destroy soil structure.Soil ecosystem restrictd acid rain forming and controled acid rain polluting.According to the condition of our country,it was put forward to excavate potential functions of soil ecosystem,build up plant's resistance to acid rain, select and popularize resistant species to acid rain and SO₂ pollution and enhance the nation's awareness of afforestation.