Mathematical equations on distribution of permeability and flow resistance of woven filter medium were deduced
and the permeability and resistance to fluid-flow of four woven filter media were calculated.The results show that the pores in a yam of plain weave filter media and among uarns of twill weave ones are very important for fluid-flow through these two kinds of filter media and the resistance to fluid-flow of woven filter media is below the smaller resistance these two kinds of pores in filter media.