To obtain a medical material excellent in blood compatibility without detriment to excellent mechanical properties inherent in a medical segmented polyurethane by compounding a specific poly(alkyl aryl ether)sulfone copolymer (A) with a polyurethane (B).

Ingredient A substantially comprises repeating units represented by formula I: -(-Ar-X-Ar1-O-)-, formula II: -(-Ar2-O-)-, and formula III: -(-RO)k [wherein X is -SO2-; Ar and Ar1 are each a 6-30C divalent arom. group; R is a 2-3C alkylene; and (k) is such a number of repeating that the mol.wt. of the polyoxyalkylene structure is 2,000-20,000] and has a content of repeating units of formula I II of 10-90 wt.% based on the sum of repeating units of formulas I, II, and III; a reduced viscosity of 0.5 or higher; and a solubility parameter of 9.0-10.3. 1-50 pts.wt. ingrediet A is compounded with 99-50 pts.wt. ingredient B.