In order to explore the functions of Orco , the gene encoding Orco from Bactrocera dorsalis (Hendel) was cloned and named as Bdor/Orco (GenBank accession No.EU621792) by RT-PCR and RACE. The sequencing results showed that the open reading frame of Bdor/Orco was 1 422 bp in length，encoding 473 amino acid residues. The Bdor/Orco was analyzed and predicted by the tools of bioinformatics in the following aspects: the composition, hydrophobicity or hydrophilicity, the signal peptide, protein secondary structure, the composition of homologous protein and the phylogenetic relationship. The results showed Bdor/Orco had the characteristics of Orco , with special conserved C domains. Tissue expression pattern revealed that Bdor/Orco transcript was observed clearly in the antenna of B.dorsalis , and highly expressed in the head (with antennae removed), female foreleg and wing. The temporal expression pattern further indicated that Bdor/Orco was also expressed in different developmental stages at different expression levels with the highest level in newly emerged female adult.