The process for preparing 4-chloro-3-hydroxy-butyronitrile

PROBLEM TO BE SOLVED: To provide a method capable of inexpensively producing high-purity 4-chloro-3-hydroxybutyronitrile, suitable for mass production. SOLUTION: In reacting epichlorohydrin with hydrogen cyanide, the reaction is carried out in the presence of an alkali metal or an alkaline earth metal sulfate, an alkali metal or an alkaline earth metal nitrate, an alkali metal or an alkaline earth metal phosphate or two or more kinds of salts of these salts in a water solvent.