[Aim] Chilo suppressalis is one of the most important insect pests in rice, and is sensitive to Bt insecticidal proteins through its cadherin (CAD) receptor. To clarify the role of the receptor in toxicity, the binding ability of CsCAD1 protein to Cry1Ac and Cry2Aa was clarified.[Method] The CsCAD1 gene fragment was cloned by PCR. The constructed pET-28a-(+) CsCAD1 recombinant plasmid was transferred into the prokaryotic expression strain BL21 (DE3) and the protein was induced by IPTG. The binding ability of the recombinant protein to Cry1Ac and Cry2Aa was analyzed by western blot and ligand blot.[Result] The recombinant vector could express a 44 ku protein in the BL21 strain, which indicated that the prokaryotic expression vector was successfully constructed. SDS-PAGE showed a single protein band, indicating purity. Ligand blot results showed that CsCAD1 recombinant protein could bind to Cry1Ac and Cry2Aa.[Conclusion] The CsCAD1 protein can bind to Cry1Ac and Cry2Aa proteins, and proved to be a potential Cry protein receptor. These results may help to elucidate the mechanism of Cry1Ac and Cry2Aa proteins on C. suppressalis.