Comparisons have been done on the experiments about the transportation and sources of nitrogen in the hillsides within a single rainfall event in south China.Results indicate that the release of the nitrogen is represented by ammonia nitrogen and ni-trate nitrogen.Transportation of the total nitrogen, nitrate nitrogen and nitrous nitrogen is dominated by infiltration process, and that of the ammonia nitrogen is dominated by the surface migration.In the case of the urea release, the migration of the nitrogen is dominated by the dissolved form of urea, ammonia nitrogen and nitrate nitrogen.The total nitrogen, dissolved urea and ammonia nitrogen is characterized by the surface migration.The transportation of the nitrate nitrogen, nitrous nitrogen and organic nitrogen is dominated by the underground infiltration process.Without human interference, rainfall-induced nitrogen deposition has become one of the main sources of the nitrogen in the experiment field.