Peeper technique was used to sample the interstitial waters in the sediments of Fubao Bay in Lake Dianchi, and the vertical distributions of NH₄⁺-N and PO₄^3--P in the waters were analyzed. The activities of microbe (the activity of FDA) and alkaline phosphatase (APA) in the surface sediments were also studied. The results showed that concentrations of NH₄⁺-N and PO₄^3--P in the interstitial waters generally increased, then decreased, with the depth, reflecting a possible diffusion trend for these nutrients. The decreasing trend was observed for the contents of organic matter (Reflected by Loss-on-Ignition, LOI), the activity of FDA and the APA in the 10cm surface sediments. The order of concentrations of NH₄⁺-N and PO₄^3--P in the interstitial waters, as well as the LOI, the activity of FDA and the APA in the surface sediments, ranked as estuary> the center of the bay > the west coast of the bay > the east coast of the bay. Regression analyses showed that concentrations of NH₄⁺-N in the interstitial water were positively correlated with the activity of FDA and the APA in the surface sediments (0-10cm), while the concentrations of PO₄^3--P were negatively correlated with them and the coefficient was very low.