Objective To investigate the features of hepatocellular carcinoma (HCC) with CT perfusion imaging. Methods Twenty-six HCC patients underwent CT perfusion imaging before therapy. Perfusion parameters of the lesion, the liver tissue around it and the distant liver tissue were measured. Results Hepatic arterial perfusion (HAP) and hepatic perfusion index (HPI) of the lesion were obviously higher than those of the distant liver tissue(P0.01), but portal venous perfusion(PVP) and total liver perfusion(TLP) were lower(P0.01). The perfusion parameters of the liver tissue around the lesion with a clear edge showed no significant difference from those of the distant liver tissue(P0.05). On the contrary, the perfusion parameters of the liver tissue around the lesion with a blurring edge were similar to the lesion. Its HAP ascended obviously, twice higher than that of the distant liver tissue. And PVP decreased. But TLP showed no significant changes. Conclusion HCC had some characteristics on CT perfusion imaging. The actual size of HCC can be determined using CT perfusion imaging.