Myofibril-bound serine proteinase (MBSP) is a recently identified serine proteinase, which is responsible for myofibrillar protein degradation and gel softing in the preparation of fish cakes. However, the full-length sequence of MBSP has never been reported. In the present study, degenerate primers were designed according to the N-terminal amino acid sequence of carp MBSP and well-conserved active site motif of serine proteinases. Based on RT-PCR and PCR amplification of the cDNA fragment from N-terminal to active site motif and rapid amplification of cDNA end (RACE) of the 3’- and 5’- regions, the full-length cDNA of MBSP was confirmed. Analysis of the nucleotide sequence of carp MBSP revealed that the cDNA clone has an open reading frame of 732 bp encoding a protein of 243 amino acid residues and a signal peptide of 21 amino acid residues. Three residues (His61, Asp107 and Ser197) forming the typical catalytic triad of serine proteinases for functional activity were conserved in the polypeptide sequence. Mature MBSP contains 222 amino acid residues with an estimated molecular mass of about 24.5 kDa, which is smaller than its native protein (30 kDa). The estimated pI of mature MBSP is 10.43. Sequence alignment showed that carp MBSP has identities of 80.6% to crucian carp MBSP, 55.8% to porcine trypsin, 55.3% to bovine trypsin, 53.9% to flounder trypsin and 39.2% to a chymotrypsin type serine proteinase mekratin, which is from the skeletal muscle of hamster. The high content (11.93%) of Lys residue distinguished carp MBSP from other serine proteinases and which may account for its myofibril-binding characteristic. Key words: Cyprinus carpio; cloning; MBSP; homology