This study simulates the rule of nitrogen conversion and its mainly influential factors in three types of water bodies ( river, stream and pond ) in Yangzhong county. The results demonstrate that the nitrogen conversion in water is affected to a certain extent by the nature of the sediment, temperature , pH, DO and the growth of algae in water. Nitrogen conversion rate in water is directly related to the available nitrogen content in the sediment. Arrhenius activation,△E= 52815. 67(J/mol). Water pH on neutrality or slight alkalinity, the increase of DO and the growth of algae all are favorable to the process of nitrification.