In order to evaluate annual dynamics of biomass for benthic faunal community, the ecological parameters (Carrying Capacity, K; Specific Growth Rate, r; Oscillation Intensity, s) of benthic faunal communities at the 70 river sites in the Tokyo metropolitan area were estimated. As a result, the value of K, r, s were in the range of 54-79479[mg/m²], 0.02 -6.40 [/year], and 0.13-5.85 [-], respectively. The statistical analysis revealed the two parameters, K and s, were related to physical and chemical factors in their habitats (e. g., dissolved oxygen and suspended solid concentrations, and discharge).