Wang, Y., Zhang, Y., Wang, F., Liu, C. and Liu, K. 2014. Development of transgenicBrassica napuswith an optimized cry1C* gene for resistance to diamondback moth (Plutella xylostella). Can. J. Plant Sci. 94: 1501-1506. Bacillus thuringiensis (Bt) cry1Ac gene has been transformed into rapeseed to control diamondback moth (DBM, Plutella xylostella), which is one of the major lepidopteran pests of rapeseed (Brassica napus). However, Cry1A-resistant DBM populations have already developed in the field. Cry1C* is a new synthetic Bt gene based on the original cry1Ca5 sequence through optimizing its codons as well as removing AT-rich sequences and inverted repeats. In our present study, the cry1C* gene was introduced into rapeseed via Agrobacterium-mediated transformation, and a total of 42 transgenic lines were recovered. The results of polymerase chain reaction (PCR) and Southern blot both confirmed the expression of the cry1C* gene in the genomes of the transformants. We also assessed the expression of this foreign gene at the mRNA level in some selected transgenic lines by real-time reverse transcription (RT) PCR analysis. Enzyme-linked immunosorbent assay (ELISA) showed that the Cry1C* expression at the protein level greatly varied among individual transgenic plants, and transgenic line 1C-8 had the highest protein level of 799.32 ng g^-1. The transgenic rapeseed plants expressing cry1C* gene showed a high efficacy against DBM. Taken together, the cry1C*-transgenic rapeseed could be employed as a useful germplasm in pest management and in the broad bioinsecticidal spectrum to prevent and postpone the development of pest resistance.