Abstract: A single nucleotide polymorphism (SNP) of sheep 805 bp sequence in 6th intron region of transforming growth factor β1(TGF-β1) gene was identified in 196 sheep among Small-tailed Han，Tong,Tan and Oula sheep by PCR-SSCP，which declared one mutation point. Comparative sequencing analysis of cloned products revealed a AGAC deletion at upstream 294 of extron 7 of TGF-β1 gene (site 14 201 in gi76871756). The statistical results of genotype and allele frequency in different breeds showed that the genotype AB dominated in the Small-tailed Han sheep. The genotype BB was in majority in low-fecudity sheep. The results of χ2 test indicated that all the populations were in Hardy-Weinberg equilibrium.