In order to study the relationship between myelocytosis protein (MYC2) gene and insect resistance of Brassica napus, we cloned the cDNA sequence of BnMYC2 gene from B. napus restorer line R18, and analyzed the gene expression and insect resistance of transformation model plant Arabidopsis thaliana. Bioinformatics analysis showed that BnMYC2 gene gDNA lack of intron structure. The cDNA complete open reading frame (ORF) was 1 833 bp, encoding 610 amino acids. The putative gene was located on the C6 chromosome of B. napus and had the conserved domain HLH of bHLH transcription factor. The results of gene homology analysis showed that BnMYC2 had the closest genetic relationship with Arabidopsis, cabbage and radish, and the similarity of amino acids was more than 98%. Tissue specific expression analysis showed that BnMYC2 was expressed in all tested tissues including roots, stems, leaves, flowers, pods 27 days after pollination and pods 35 days after pollination, and the expression level was the highest in pods 27 days after pollination. The results of insect resistance experiment showed that the expression level of insect resistance gene VSP2 in overexpressing BnMYC2 Arabidopsis was significantly higher than that in the control. It is speculated that BnMYC2 gene in B. napus may participate in the response to insect stress as an important regulator. After 6 hours of MeJA induction, the expression of VSP2 gene in different genotypes of Arabidopsis was significantly higher than that before induction, indicating that BnMYC2 positively regulates the expression of VSP2 gene. It is speculated that BnMYC2 can make plants respond to insect stress by regulating the expression of multiple marker genes including VSP2.