Abstract: Insects can specially recognize the opposite sexes of the same species. PBP1, OR1 and OR3 play an important role in the process of the male silkworm Bombyx mori perception and location of the females. For the purpose of finding out the molecular mechanism of difficult hybridization of B. mori and B. mandarina, and understanding the evolution of related genes to sexual recognition between the two species, we cloned three genes (Bmmpbp1, GenBank ID: GQ246497; Bmmor1, GenBank ID: GQ246496; Bmmor3, GenBank ID: GQ246498) of wild silkworm B. mandarina. Sequences analysis revealed that between the two species there were 4 singlenucleotide polymorphisims (SNPs) (C10A, A40T, T270C and A333G) in pbp1, two of which caused amino acid variation (Q to K, N to Y); there were 5 SNPs (T910C, A1147C, A1192T, T1276C and G1282A) in or1 and only 1 induced amino acid variation (F to L), and there were 4 SNPs (A507G, A513G, T605C and G672A) in or3 and 1 caused amino acid mutation (I to T). The genetic distances of the three genes are close and the evolution velocities are low. Secondary structure predicted by PHD program on line suggested that mutation sites had no influence on the adjoining regions, or on the functional sites. There are presumably no functional differences in these genes of the two related moths. Namely, male and female individuals could perceive and recognize mutually between the two species. Our findings were consistent with the experimental observations.