Objective:To evaluate the expression level and the diagnostic role of GDF 15 as a potential tumor marker in small hepatocellular carcinoma(SHCC) in human beings. Methods:Based on the previous data of Affymatrix microarrays,which indicated an over-expression of GDF15 in early-stage HCC of rat models,transcription level of GDF15 was examined in both rat models and human SHCC by RT-PCR. Real-time quantitative PCR was used to quantitatively analyze the gene in ten human small hepatocellular carcinoma and ten normal liver tissues,respectively. The protein levels and expression sits were subsequently confirmed in the SHCC,single large hepatocellular carcinoma(SLHCC), paraneoplastic tissues and normal liver tissues of human by immunohistochemistry(IHC),respectively. Results:GDF15 expression was significantly higher in the rat and human SHCC than in the normal liver tissues(P < 0.05). Real-time quantitative PCR and IHC analysis revealed that GDF15 expression was also higher in SHCC than in the paraneoplastic liver tissues and normal liver tissues. GDF15 protein detected in all 12 SHCC was mainly observed in the cytoplasm and extra cellular matrix of tumor cells. Conclusion:The current results showed GDF15 expression was high in the SHCCs and suggested it should be a useful tumor marker in detecting SHCC.