Objective:To obtain information at the molecular level on the possible mechanism of MXR7 gene overexpressed in hepatocellular carcinoma (HCC) and also to provide a clue for further study. Methods:Genomic DNA was isolated from 20 samples of hepatoma and paired non-HCC liver tissues, 2 cases of blood tumor and two types of cells (HepG2, MCF-7) and digested with two kinds of endonucleases (EcoR Ⅰ and EagⅠwhich is methylation sensitive endonuclease). And the condition of MXR7 gene methylation was examined and analyzed by South blot. Results: MXR7 was unmethylated neither in tested tumorous liver samples nor in paired non-HCC liver tissues. In addition, the same result was found in 2 blood tumor samples and HepG2. Only two paired samples had different methylation outcome, one was unmethylated and the other was partly methylated. Conclusion: MXR7 is unmethylated in HHC, suggesting methylation of MXR7 may have no relation with its expression and regulation.