Abstract: In this study we cloned partial cDNA sequences of Lmbr1 gene from a normal pig and a polydactyly pig by RT-PCR and RACE and analyzed the sequences. The results showed that the cDNA sequence from the normal pig was 1 797 bp,including 1 178 bp in CDS and 619 bp in 3′UTR.The cDNA sequence from the polydactylous pig was 1 069 bp,including 768 bp in CDS and 301 bp in 3′UTR. the CDS sequences similarity of Lmbr1 gene was near 77% between the normal pig and the polydactyly pig, while the 3′UTR sequences similarity was below 20%.There were 13 mutations among 755-768 base pairs between the CDS sequences, including G755C, A756T, A757G, T758C, C759A, A760G, C761T, T762G, A763C, G764T, A765G, T767G and T768A.The former 11 mutations belonged to missense mutations，which resulted in 4 amino acids change, including G → A, I → A, T → V and R → L. The later 2 mutations belonged to nonsense mutations，which resulted in the termination of ORF in advance. It is presumed that the fundamental reason for the form of the polydactyly pig is the mutations of Lmbr1 gene, which could result in the exceptional expression of SHH.