A local isolate of Bacillus thuringiensis Mm2 had insecticidal activity against the larvae of Melolontha melolontha, Agelastica alni, Leptinotarsa decemlineata and Amphimallon solstitiale and produced a 65 kDa protein. SDS-PAGE profile of B. thuringiensis Mm2 was compared with those of 29 different Cry3Aa producers which verified Cry3Aa biosynthesis by the isolate. The cry3Aa gene of Mm2 was cloned, sequenced and the deduced amino acid sequence was compared with the cry3Aa sequences of ten different quaternary ranks. Its identity to these sequences ranged between 97.4% and 99.2%. The gene was next cloned into E. coli-Bacillus shuttle vector pNW33N and expressed at a low level in B. subtilis 168.