PURPOSE: To provide a quick-hardening binder, having both simplicity of a resin emulsion and reliability of improved characteristics with an impregnated polymer and increased in strength.

CONSTITUTION: The objective quick-hardening binder is obtained by adding gypsum in an amount of ≤30wt.% based on a quick-hardening clinker composed of 11CaO.7Al2O3.CaX2 (X denotes halogen atom) and a Portland cement clinker mineral to the quick-hardening clinker, providing a quick-hardening composition and then respectively adding a water-soluble melamine resin such as methylolmelamine, methyl etherified melamine and a modified substance thereof in an amount of 1-20 pts.wt. based on 100 pts.wt. quick-hardening composition and citric acid in an amount of ≥0.05 pt.wt. based on 100 pts.wt. quick- hardening composition thereto.