In this study, the concentrations and distributions of Zn, Pb, Cd, Ni in sediments in Lake Caohai from Weining District of Guizhou Province were analyzed in this research based on atomic absorption and ICP-MS, and its influence on zoobenthos community was analyzed. The results indicated that, concentrations of Zn, Pb, Cd in surface sediments exceeded the Canadian Environmental Quality Guidelines The percentage of samples contaminated by Zn, Pb, Cd, were 82%, 65% and 47% respectively. This may be due to the historical zinc smelting activities. But concentrations of heavy metals in surface water and pore water of Lake Caohai were in normal range compared to the National Quality Standard for Surface Water (grade I), which indicated the influence of heavy metals in contaminated sediments on pore water was limited. Concentrations of Zn, Pb, Cd, in the middle of the lake and at the shore were higher than those in other sampling sites. Pearson correlation coefficients between the content of Zn, Pb, Cd, and organic materials were positive in significant levels (r=0.837, P < 0.01; r=0.785, P < 0.01; r=0.780, P < 0.01, respectively), which meant the content of organic materials played an important role in transformation and deposition of these heavy metals. Concentrations of Zn, Pb, Cd were rising and accumulating from 10cm to the top of sediment profile in the middle of Lake Caohai, which could match with the history of zinc smelting activities in recent decades. Ni had an opposite correlation with the other three studied heavy metals in both surface sediment and sediment profile, probably because Ni came from the natural background. The survey of zoobenthos community structure indicated that there were more species and higher density of zoobenthos in the surrounding sampling sites than those in the central area. This may suggest a higher concentration of heavy metals in the central area of Lake Caohai. Further studies are needed to justify this.