Acid deposition and soil erosion have deteriorated human living environment, w hich has aroused a general concern from people all over the world.The erodibility of acid deposition on soil from the angle of aggregate is studied.Analyzing of the e fects of acid deposition on soil system showed that acid deposition affects soil aggreeation and organo-mineral complex mainly by altering soil acid-based condition,soil colloidal stability and the amount and property of soil cemedins.The influences made soil aggregation decreased,clay content increased and finally soil erodibility enhanced.Obviously, long-time acid deposition plays an important role in soil erosion.