Objective To analyze plasma apolipoprotein M (ApoM) level and hepatic apoM mR-NA level in the hepatocellular carcinoma (HCC) patients.Methods Plasma apoM levels were measured by the dot-blot analyses in 36 HCC patients, and 64 normal subjects as control.APOM mRNA levels were detected in the HCC tissues and paracancerous normal liver tissues by RT-PCR, and further conformed by an immunohistochemistry staining method.Results The relative levels of plasma apoM in HCC patients were (0.61 ± 0.30) ODu·mm-2, which were significantly higher than those in the normal subjects [(0.37 ± 0.07) ODu · mm-2] (p < 0.01).apoM mRNA levels in HCC tissues were significantly lower than those in the paracanerous normal tissues (P < 0.05), which was further confirmed by the immunohistochemistry staining.APOM positive staining in HCC tissues was significantly weaker than that in the cancerous normal tissues.Conclusion In HCC patients, apoM mRNA levels in tumor tissues were significantly lower more than those in the paracancerous normal tissues, and plasma apoM levels were significantly higher than those in normal subjects. Key words: Carcinoma,hepatocellular; Apolipoprotein; Immunohistoehemistry