A review.3-Me-2-oxo-butanoic acid was a kind of bifunctional compound with special and active nature.It was an important intermediate for drug synthesis and biol. transformation.And its calcium salt, as an effective drug, was used to treat urinary disease for many years.The main synthesis methods of 3-Me-2-oxo-butanoic acid were reviewed.Combining technol. features, a detailed comparative anal. of preparation methods, suitable for industrial production, was supplied.