Current species diverstity, standing crop(density and biomass) and distribution on zoobenthos in 4 main parks of Tianjin City are investigated. 3 kinds of biotic index measurements are performed. Based on the present study and referring to the information from the studies on allied domestic water bodies, an ecological and environmental status of the investigated area is assessed and evaluated. Research results suggest the water quality of Water Park can be delimited to light organic pollution. Beining and Xigu Parks belong to light meso polluted type. Changhong Park is seriously polluted.