Abstract: To assess the impact of the Water Environment Governance Engineering on the nutritional status of water in Lihu Lake, this paper explored the spatial distribution characteristics of Nitrogen fractions and its influencing factors of the water and surface sediments in Lihu Lake by investigating totally 64locations in the lake and the lake estuaries in April and October, 2012. The results showed that the ρ(TN) contents in the overlying water in Lihu Lake ranged from 0.82to 3.20mg/L with the mean value of 1.35mg/L, while ρ(DTN) in the interstitial water was 1.28to 5.36mg/L with the mean value of 2.51mg/L. Both of the two parameters increased from the west to the east. Meanwhile, the ρ(TN) was higher in the estuaries than in the lake. Average diffusion flux of NH₄⁺-N during the study period is 4.80mg/(m².d) and there is a significant positive correlation of the diffusion fluxes of NH₄⁺-N and the concentration of w(E-NH₄⁺-N) and w(TN) in the surface sediment. The eutrophication problem has not been completely solved yet. As exogenous pollution had been controlled, although the water quality of Lihu Lake has been significantly improved by a series of water treatment projects launched in 2003. More attention should be paid to the recuperation of the submerged plant and the optimization of the ecosystem structure of Lihu Lake.