The aim of the study was to characterize the polymorphism of the Calpastatin (CAST) gene identified with three restriction enzymes (TaqI, HinfI, MspI) in Meishan and five other pig populations, and to provide information on their potential in marker-assisted selection and conservation. Meishan pigs appeared to be monomorphic at loci CAST/HinfI and CAST/MspI. A high frequency of the favoured genotype, FF, in terms of meat quality was detected in Meishan pigs, a breed well known for high quality meat. However, the frequency of the genotype, FF, was very low in Sutai pigs, a breed developed from a Duroc (50%) x Meishan (50%) cross. This is probably partially due to the fact that genetic improvement in this breed was achieved through the use of traditional quantitative genetics. It is suggested that traditional selection techniques combined with the use of the polymorphisms discovered have an important potential to improve overall meat quality.