Abstract: Mlo(barley powdery mildew resistance gene) gene family is a kind of negative regulator of plant resistant to disease,mutations in this gene can be resistant to a wide variety of diseases.The rice Mlo gene(GenBank accession number:AK099399.1) was served as an information probe in the tobacco EST database and a cDNA sequence of tobacco Mlo was obtained by assembling the obtained ESTs with high homology.A cDNA fragment of tobacco Mlo gene with the expected size(951bp) has been successfully cloned by RT-PCR,the cloned gene could encode 304 amino acids.The primary and secondary structure of protein encoded by the cloned gene was predictively analyzed by bioinformatics and the functions of the same were predicted as well.The results showed that the encoded protein had a conservative structural domain Tmemb_40 and it might be a membrane-bound transporter protein similar to the G protein-coupled receptor in plant.