To produce a polyurethane emulsion improved in solvent resistance, water resistance, and miscibility with other aqueous emulsions by reacting an isocyanate-group-containing polyurethane prepolymer with an amine polymer and a specific low-mol.-wt. compound in an aqueous medium.

A high-mol.-wt. polyol having a number average mol.wt. of 500-10,000 and a hydroxyl functionality of 2.0 or higher but not higher than 4.0, an organic diisocyanate, and if necessary a chain extender are reacted in the absence of a solvent to give a polyurethane prepolymer having isocyanate groups. The prepolymer in an amount of 100 pts.wt., 0.2-20 pts.wt. amine polymer having a mol.wt. of 100 or higher, and a low-mol.-wt. compound having a mol.wt. of 300 or lower, containing active hydrogen groups selected from among prim-amino, sec-amino, prim-hydroxyl, and sec-hydroxyl groups, and in an equivalent ratio of active hydrogen atoms to isocyanate groups of the prepolymer of 0.70-1.20 are reacted in an aqueous medium.