The determination of the liquid velocity profile in packed bed pores is a well-known problem in the practical applications and the theory of filtration and separation processes. Because the pore sizes are very small, the measurement of the liquid velocity in these areas is very difficult or impossible. By using the modified Kuwabara-Happel cell model, the liquid velocity profile in the pores of packed bed consisting of solid spheres and cylindrical wires was determined. The variation of the liquid velocity with the packed bed porosity and pore geometry has been investigated. By using these results, the expressions for drag force affecting the small particles in the pores and particle capture radius in magnetic filter have been obtained. The effect of the variation of some parameters of filtration system on the particle capture radius has been investigated. Comparisons of the theoretical and experimental results were found to be in good agreement.