Disclosed herein is a novel enzymatic agent effective in reducing acetaldehyde in the oral cavity. It has been found that an aldehyde dehydrogenase derived from a microorganism belonging to the genus Saccharomyces and a threonine aldolase derived from Escherichia coli are effective in reducing low concentrations of acetaldehyde. Therefore, an agent for reducing acetaldehyde in the oral cavity is provided, which contains these enzymes as active ingredients.
