In this paper, the characters of hydrodynamic permeability, surface property, and blood compatibility of polydopamine (PDA) coated polyethersulfone (PES) ultrafiltration (UF) membranes were investigated in detail. We presented a general protocol to improve the hydrodynamic permeability and blood compatibility of PES UF membranes by a simple biomimetic strategy. The chemical structure and surface morphology of the PDA coated membranes were studied in detail; meanwhile, the influence of the coated PDA nano-layer on water contact angle and water flux of the modified membranes was investigated. It was found that the water flux of the pure PES membrane decreased dramatically, approach to 0 ml/(m(2) h mmHg), after a few hours of PDA coating. To avoid the dramatic decline of water flux, the method of pre-adding pore-forming reagent was taken to fabricate the PDA coated PES membranes with tunable water flux. Moreover, the anti-fouling property, platelet adhesion, and blood coagulation time of the PDA modified PES membranes were studied, and the results indicated that the PDA modified PES UF membranes showed enhanced blood compatibility. (C) 2012 Elsevier B.V. All rights reserved.