NADH-cytochrome-b 5 reductase (CbR) was a flavoprotein and multi-funct ional redox enzyme, purportedly shuttled electron to the substrate-complex for various physi ological reaction, such as the P450s metabolism rea ction, desaturation and elongation of fatty acyl-CoA etc., and was potentially used in food industry, biosens or and diagnostic areas. In this work, two full-length cDN As of SeCbR genes, with the different N- terminal n ucleotide sequence, were isolated and partially characterized . The cloned SeCbR1 (SeCbR-like3) and SeCbR2 (SeCbR -like2) had complete open reading frame, were predicted to encode 324 and 311 amino acids respectively, and sh ared high identities with CbRs of several other species. For disclosing more information of SeCbR1 and SeCbR2, b oth genes were analyzed by bio-information software and detec ted with RT-qPCR method. Both genes had the trans-m embrane segment at the N- terminus. And the phylogenetic tr ee result showed that both genes are belong to the CbR family and had closest relationship to the CbR of Helicove rpa armigera. The RT-qPCR results signified that Se CbR1 and SeCbR2 expressed in most developmental stages of S. exigua except egg, as well as in tissues of cuticl e, fatbody and midgut. It is anticipated that our initial finding of SeCbR1 and SeCbR2 genes could generate the basem ent for further studies of them at the molecular level. (words 204; limitation 250)