A full-length cry1Ia gene fragment, obtained by polymerase chain reaction (PCR) amplification with a pair of primers designed according to cry1Ia-type gene sequences and DNA from Bacillus thuringiensis as template, was introduced into the expression vector pET-21b and transformed into Escherichia coli BL21(DE3). The molecular weight of the induced expression product was 81.2 kDa. The amino acid sequence of Cry1Ia was very different from sequences of 12 known Cry1Ia-type proteins. This gene was designated as cry1Ia8 by the International B. thuringiensis Insecticidal Protein Nomenclature Committee (accession number AF373207). The bioassay results indicated that Cry1Ia toxin protein showed distinct insecticidal activity against Ostrinia furnacalis and Plutella xylostella with LC50 of 0.268 μg/g and 2.227 μg/ml, respectively. It also had insecticidal activity against Leguminivora glycinivorella, but not against Pyrrhalta aenescens. The novel cry1Ia8 gene will be an important resource in constructing genetically engineered bacteria and transgenic plants for biocontrol of insect pests. It is also available for screening gene stacks to delay pest resistance.