Objective:To explore the effect of angiogenesis and its maturation of hepatocellular carcinoma (HCC) on biological behavior. Methods In thirty-one cases of HCC proved by surgery and pathology two sections from the tumor periphery and center area were removed. Continuous slices were stained with immunohistochemistry of five antibodies against VEGF, Flk-1, PCNA, CD34 and α-smooth muscle actin (SMA). Expressions of VEGF, Flk-1, and PCNA, vessel numbers, mean area, overall area, circumference, diameter, distance between adjacent vessels (DAV), and variety index of microvessels and mature vessels were counted. The arterioles and veinlets, mature vessel index and mean perfused fraction (mPF) were also calculated. The relationships between the above vascular parameters and diameter, Edmondson′s grade, capsule of HCC and cirrhosis were analyzed. Results There were differences in the overall area of micro-vessels and mature vessels among different diameters of the lesions (P<0.05). The mPF gradually became higher with the increase of Edmondson′s grade, and a statistical difference was found (F=3.452, P=0.049). The mean area, circumference, diameter and DAV of mature vessels were more in tunicary lesions than in non-encapsulated ones (P<0.05). Also, the variety index of mature vessels was higher in the invasive group than in the non-invasive one (t=2.260, P=0.039). No differences in any vascular parameters were shown between the cirrhotic and non-cirrhotic groups (P>0.05). Conclusion Some behavior of HCC may depend more on the mature vessels than on the micro-vessels.