Optically active chiral organic sulfur-containing compounds play an important role in biochemistry and pharmaceutical chemistry.[1] Asymmetric sulfur-Michael addition(SMA)represents a fundamental method for creating carbon-sulfur bond in an asymmetric fashion.[2] Various catalytic asymmetric SMAs employing alkyl or aryl thiols as sulfur nucleophiles have been developed over the past few decades.[3-6] Herein,an organocatalytic enantioselective sulfur-Michael addition of thioacetic acid to arylmethylidenemalonates was developed with high yields and up to 97%enantiomeric excess.Both enantiomers of the products were accessible with two different organocatalysts.The current method provides the first,practical,and convenient preparation of enantiomerically enriched acetylthiomethylmalonate derivatives.