Abstract: The porcine cathepsin B (CTSB) nucleotide and amino acid sequence were obtained by RT-PCR and sequencing. The open reading frames (ORFs) were 1 008 bp long (encoding for 335 amino acids). The nucleotide sequence identities of porcine cathepsin B ORFs were 85%, 81% and 90% comparing to that of the human, rat and bovine, respectively. The deduced amino acid sequence identities of the porcine cathepsin B protein were 81%, 79%, and 91% comparing to that of the rat, human and bovine, respectively. The structure of cathepsin B protein was predicted by homologous modelling which was similar to other papains. The substratebinding cleft and the catalytic triad were found in the structure model. The polymorphisms of porcine cathepsin B gene was detected in 147 pigs by PCR-SSCP. There were six genotypes be detected on the SSCP locus. The genotype FF on CTSB gene SSCP locus had the highest tenderness traits, it had significantly higher shear force (6.56 kg) and toughness (23.55 kg·s) than genotype EE and EF (P<0.01), and it had significantly higher mean shear force (4.85 kg) than genotype EF (P<0.05).