The polymorphism in a fragment within the coding region of the inhibin a subunit ( INHA ) gene was studied in 323 heads of Matou, Nubi, Boar and Haimen goats by PCR-SSCP, PCR-RFLP and sequencing. A new mutation G284A (Accession number: L28815) was identified, which could be detected by Hae digestion of a PCR product spanning this site. Hae PCR-RFLP analysis indicated that allele G was dominant. Association studies indicated that the effect of INHA genotypes on litter size was greatest for GG, followed by AG and AA genotypes. Thus, INHA may be a major gene controlling the prolificacy of goat, and allele G is positively correlated with litter size.