Abstract: Objective To investigate the expression and clinical significance of Platelet-Derived Growth Factor-D(PDGF-D) in hepatocellular carcinoma (HCC)． Methods PDGF-A，B，C，D and PDGF receptor （PDGFR）α and β mRNA level was assessed by reverse transcription-polymerase chain reaction（RT-PCR）in 40 cases HCC tissues，30 cases of paracarcinoma tissues and 10 cases of normal liver tissues． Results PDGF-A，B，C，D and PDGFRα，β mRNA level was 37.5%，70.0%，52.5%，92.5%，22.5%，42.5% in HCC, 23.3%，16.7%，16.7%，26.7%，13.3%，16.7% in paracarcinoma tissues respectively．No expression of PDGF-D mRNA was found in the normal liver tissues．PDGF-D mRNA expression was significantly higher than that in paracarcinoma tissues and normal liver tissues，there were significantly differences among three groups（P＜0.01）.Moreover, the expression of PDGF-D mRNA was significantly higher than PDGF other isoforms in HCC tissues(P＜0.05)．Average photodensity of PDGF-D were 0.5900±0.0364，0.3954±0.0654 and 0 in HCC，paracarcinoma and normal liver tissues，there were significantly differences among three groups（P＜0.01）．PDGF-D mRNA expression were related to tumor differentiation degree，metastasis，but not to gender，age，tumor size and portal vein cancer embolus（P＞0.05）． Conclusion PDGF-D mRNA expression was significantly higher in HCC and were related to tumor differentiation degree and metastasis．PDGF-D may play an important role in the carcinogenesis，development and metastasis of HCC，as a clinical diagnosis index and a potential target for therapy in HCC．