PURPOSE: To produce the subject composition excellent in weather resistance and resistance to moist heat and useful as coating, binder, etc., by compounding an aqueous polyurethane obtained by reacting a specific urethane prepolymer with a chain extender and water.

CONSTITUTION: This polyurethane composition is produced by compounding an aqueous polyurethane obtained by reacting a tertiary amine or an ammonia neutralization product of an urethane prepolymer having carboxyl groups and terminal isocyanate groups with a chain extender such as ethylene diamine, with water used as a solvent. The urethane prepolymer is obtained by reacting a diisocyanate with the mixture of (A) 55-98wt.% of a polycarbonate diol obtained by reacting a dial mixture containing 1,4-cyclohexanedimethanol and 1,6-hexanediol as essential components with a carbonate, (B) 2-25wt.% of a dimethylol alkanoic acid and (C) 0-20wt.% of another polyol.