A chymotrpsin gene homologue was cloned from the mulberry longicorn beetle, Apriona germari. The A. germari chymotrypsin cDNA contains an ORF of 950 nucleotides capable of encoding a 283 amino acid polypeptide with a predicted molecular mass of 29151 Da and pI of 9.38. The A. germari chymotrypsin has conserved six cysteine residues and active triad formed by His, Asp and Ser. The deduced amino acid sequence of the A. germari chymotrypsin cDNA was closest in structure to the Anthonomus grandis chymotrypsin. Northern blot analysis revealed that A. germari chymotrypsin showed the midgut-specific expression.