Blend membranes of cellulose and polyethersulfone ( PES) were prepared by using the mixture of DMAc / LiCl as solvent of cellulose. The influence of blend ratio on tensile strength, elongation at break, and pure water flux of the blend membrane was discussed. The optimal blend ratio of cellulose / PES was determined to be 1 : 16. SEM and DSC analysis was carried out on the blend membrane. The results showed that the cellulose / PES blend membrane is a compatible system.