Abstract: The classification of chitinases in 50 crustaceans was reviewed and it was verified that chitinases in crustaceans could be subdivided into group 1-group 7 according to the classification of amino acid homology. The structure and the function of chitinase in crustaceans were focused in this review. In terms of structure, the characterization of conserved motifs based on amino acid sequence, as well as the composition profile of several domains of group 1-group 7 chitinases were discussed. Then, the three-dimensional structure of one of chitinases from P. trituberculatus, which was considered as a symbol of the crustacean chitinase, was predicted. The functions of crustacean chitinase were further stated and it generally participated in the digestion of chitinous food, in the digestion of old shells during molting, as well as degrading the chitinous cell wall of pathogen to exert its function on immune defense.

Key words: crustaceans, chitinase, structure, domain, physiological function