Polyol component essentially consists of polyesterpolyetherpolyol containing polyesterpolyol by the weight ratio of 100:0 to 20:80, in which the polyesterpolyetherpolyol is a copolymer of polytetramethyleneglycol (PTMG) and .epsilon.-caprolactone by the weight ratio of 20:80 to 80:20 with an average molecular weight of 1000 to 3000 and the polyesterpolyol is a condensate of adipic acid as a main acid component with an average molecular weight of 1000 to 3000, is reacted with isocyanate component essentially consists of 4,4'-diphenylmethanediisocyanate (MDI) to make a prepolymer with terminal radical of NCO.Microcellular polyurethane produced from the prepolymer by foaming and polymerization reaction has the durability for vibration-proof material of car use, combining the advantage of PTMG such as high initial modulus at elongation, low heat built up, low-temperature property and hydrolysis-durability under high humid and hot conditions, with the advantage of polycaprolactone such as good molding property and anti-bending-fatigue property, as well as making up for the disadvantage of both polyols each other. Thus improving the problems of microcellular polyurethane using MDI such as low initial modulus at elongation and high heat built up.