Application of porous polymer materials to novel bio-interfaces for tissue engineering scaffold and artificial organs including blood filters, dialyzer, and oxygenator membranes have been in progress. The present study describes the fabrication and characterization of self-organized highly regular porous polymer films with uniform pore sizes are prepared by simple casting technique. Various fabrication parameters affecting the pore size such as polymer concentration, boiling point of solvent, cast volume and substrate are studied. The pore size can be controlled in the range from 1 to 50 microm by changing the evaporation rate of the polymer solutions. The porous film with uniform pore size is used for tissue engineering scaffold and cell separation membrane. To simulate the leukocyte eliminating from human blood, the porous film was attached to a module. The films with 5-9 microm pores provided the complete selectivity of separation for the leukocyte from the whole blood. The leukocyte elimination ratio depends on pore structures (size and depth) as well as recovery of platelet and erythrocyte.