In order to investigate the species distributions of nitrogen and phosphorus in Surface Sediments and the contents of multiple nitrogen and phosphorus forms in surface sediments and interstitial water, the test samples are collected from six representative sampling points of Datong Lake. The results show that the average contents of total nitrogen and phosphorus in sediment are 1912.9 mg/kg and 2144.5mg/kg respectively. The contents of nitrogen and phosphorus from different sampling point are different. The organic nitrogen, accounted for 93.50%-97.12%, is the main form of nitrogen and inorganic phosphorus accounts for 80% in phosphorus. The ratio of Ca-P to that of Fe-P and Al-P in inorganic phosphorus is about 1:1. Through the correlation relationship analysis of phosphorus species distributions in sediments and interstitial water, we can conclude that the phosphorus is hard to release from sediment to interstitial water and exogenous elements have a great influence on the contents increase of nitrogen and phosphorus.