To enable stable production of urethane emulsion that is useful as a coating material or the like, even when 1,6-hexanemethylene diisocyanate is used as a starting material by dispersing a urethane prepolymer in water and chain-extending the urethane prepolymer with a specific amine compound.

(A) A urethane prepolymer with 2-15wt.% residual isocyanate group content prepared by polymerizing (A1) polyisocyanate including 1,6- hexamethylene diisocyanate, (A2) a compound bearing 2 or more functional groups (G) bearing active hydrogen atoms reactive with isocyanate groups and carboxyl or sulfonic acid group and (A3) a compound bearing 2 or more G is dispersed in (C) water in the presence of (B) a hydrophilic organic solvent. Then, (D) an aromatic polyamine compound or an alicyclic polyamine compound [for example, 4,4'-diaminodiphenyl-methane, 1,3-bis(aminomethyl)cyclohexane] is used to extend the chain of the urethane prepolymer.