In the present paper, the Brownian dynamic simulation method is applied to study the initial deposition behavior of colloidal particles onto the collector surfaces in a filtration bed. By using four different porous media models, Kuwabara, Happel and N-M model I (when Darcy's equation is adopted) and N-M model II (when Brinkman's equation is adopted), to characterize the flow field around the collector, the effects of the total interaction energy curves of various shapes and the magnitudes of the porosity of porous media on the collection efficiencies of Brownian particles are examined. Under the same simulation condition, it is found that the highest collection efficiency is always obtained when the N-M model I is used in the Brownian dynamic simulation of the present paper. Comparing with the published experimental data of measuring the deposition rates of Brownian particles, it is found that the simulation model of the present paper can give a good simulation result for the experiment of the attractive double layer interactions. Disparities between theoretical predictions and experimental data are observed for the experiment of the repulsive double layer interactions at the unfavorable deposition region. (C) 2002 Elsevier Science B.V. All rights reserved.