In this study, a design method of a bio-retention pond for reducing suspended solids at an industrial area is proposed. After simulating suspended solid loads at a study drainage catchment using SWMM calibrated with the unit load estimation method which is recently suggested by the National Institute of Environmental Research, the non-point pollutant reduction efficiency with respect to the bioretention capacity is quantified. Based on various simulation results, the stormwater captured ratio curve and the average annual fraction of suspended solid loads controlled by a bio-retention pond are derived. Using the regression analysis, coefficients of the formula for the average annual captured fraction of suspended solid loads, which is missing in the Korean TMDL technical guide, is proposed.