Abstract: The effect of light fraction organic matter (LFOM) on nitrogen (N) and phosphorus (P) mineralization in the sediments of Taihu Lake was investigated under continuously water-logged incubation. The sediments fromYuantouzhu (Y) and Gonghu (G) at different pollution levels were used. The results showed that the effect of LFOM removal on N and P mineralization of differenttrophic sediments was similar. At the early stage, the amounts of N and P mineralization increased quickly, but later the extent decreased; after reaching the peakvalues, the amounts decreased to the lowest at 42 d and then stayed minimum until the end of the incubation. During 77 day anaerobic incubation, the results showed that 24%-39% of TN and 7%-26% of TP of the studied sediments were mineralized. The amounts and rates of N and P mineralization from the heavily polluted sediment Y were higher than those of sediment G, in which the amounts and rates decreased after removal of the LFOM. In sediment Y, the amounts of N and P mineralized decreased 110.86 mg/kg (amounts to 15%) and 145.26 mg/kg (74%), respectively; in sediment G, the amounts decreased were 195.13 mg/kg (40%) and 29.99 mg/kg(50%), respectively. After the LFOM removal, the average mineralization rates of N and P decreased 3.01 mg/(kg·d) and 5.36 mg/(kg·d) for sediment Y, and 6.35 mg/(kg·d) and 1.30 mg/(kg·d) for sediment G, respectively.