Expression of insecticidal protein by fusion product of truncated HD-1 [CryIA(a)] N-terminal and HD-73 [CryIA(c)] C-terminal fragment of Bacillus thuringiensis subsp. Kurstaki was investigated. Immunological analysis of transformants by using polyclonal antisera raised against the whole-crystal protein of HD-1 revealed that SK4 and SK5 were observed cross-reaction with polypeptides of 77-kDa and 105-kDa, respectively. Bioassay of the transformant pSK5 to Plutella maculipennis and Heliothis assulta were 96% and 97%, respectively.