The interpenetrating polymer networks (IPNs) of poly-50.5 dyne/cm, and polarity ranged from 0.59 to 0.91. The urethane (PU) and 2-hydroxyethyl methacrylate (MEHA)-relative index of platelet adhesion (RIPA) of the IPN memterminated polyurethane (HPU) were prepared by solution branes was measured by the dynamic thrombosis test at polymerization. PU prepolymer was synthesized from 4,4-constant shaking speed and temperature. By the criteria of diphenyl methane diisocyanate (MDI) and poly(propylene this test, the IPN membranes with HPU content of about oxide) glycol (PPG). HPU prepolymer was synthesized from 25 wt % have the minimum platelet adhesion. When mea-MDI, poly(tetramethylene oxide) glycol and HEMA. Dy-sured by the angular dependent ESCA technique on the namic mechanical analysis showed that the resultant IPN surface of IPN samples, the variation in the RIPA correlated membranes have good compatibility between their constit-to the change in the surface soft segment to hard segment uents. As the HPU content increased, the tensile strength of ratio. Higher HPU content resulted in more migration of the IPNs first increased and then decreased. For the highest soft segments toward the surface. The platelet adhesion was tensile strength, the optimum HPU content was about 25 wt observed to be minimized when the surface O/N ratio was %. The value of surface tension of IPNs varied from 44.4 to around 12.