To scarcely develop troubles on the working circumference and on the treatment without developing offensive order at the time of collapsing binder by containing a specific quantity of easily-water-soluble and basic amino group compound to water-soluble molding sand remover used at the time of removing the molding sand stuck to a kneader, molding machine, etc.

The used amino group compound is selected to one or more among group of methoxy propylamine, ethyoxy propylamine, dimethyl formamide, iminobis propylamine, dimethyl acrylamide, methylpyrolidone, pyrolidine, bengylamine, cyclohorylamine and tetramethyl diamino propane. This content is 0.1-80wt.% standard at the time of using the remover and further, it is desirable to add interface activator of alkyl betain, etc., and a thickner of liquid polyethylene glycol, etc.