Based on transcriptome sequencing of Rosa longicuspis and R. odorata, 23 MLO-likegenes were identified from the transcriptome data and analyzed by using bioinformatical methods. The results showed that between R. longicuspis and R. odorata, the number of amino acids, base pairs and molecular weight of different proteins coded by genes did not vary significantly. Most of the protein were hydrophobicin with the average hydrophilic coefficients of -0.157-0.190. And these protein were rich in leucine and serine. By bioinformatics prediction, the deduced proteins of MLO–like genes were mostly located to the plasma membrane, with 5-9 predicted transmembrane motifs. Of that, the isoelectric point of one protein was less than 7.0, and two proteins contained predicted signal peptides. These 23 MLO proteins had 15 conserved motifs with length varying from 15 to 50 amino acids. The phylogenic analysis revealed that 23 MLO unigenes were highly homologous and conserved. By search for sequence homolog in Arabidopsis thaliana, six genes were identified to be associated with powdery mildew resistance in A. thaliana, two of which resembled the typical structure of MLO genes. qRT-PCR revealed up-regulation of these two genes was up-regulated post powdery mildew inoculation. Thus, this work suggested two MLO-like genes that possibly associated with powdery mildew resistance.