Abstract: Objective : To evaluate the effect of intraoperative ultrosound guided segmental staining by portal vein branch to the tumor for the hepatectomy of liver cancer. Methods : Forty-five patients with hepatocelullar carcinoma (HCC) were divided into the experiment group (22) and the control(23) randomly. Hepatectomy was performed under ultrosound guided segmental staining by selective portal vein branch catherterization in experimental group, and tranditional hepatectomy was performed in control group under same condition. The achievement ratio was observed in experimental group, and the operating time, bleeding volume and the complication were compared between the two groups. The results of ultrasound and of pathology both in preoperation and intraoperation were compared. Results :The achievement ratio of segmental staining was 86.4%(19/22) in experiment group. There was no significant difference between operating time, bleeding volume and complication and the diagnosis rate of 63 tumer nodes (45 cases) under intraoperation ultrosound was significantly higher than that of preoperation ultrosound (98.4 % vs 84.1 %, P<0.05), so did the diagnosis rate of cancer embolus (94% vs 52 %,P<0.01). Conclusion : Intraoperation ultrosound plays an important role in the clinical plan of hepatectomy. Segmental hepatectomy might be performed under intraoperation ultrosound guided segmental staining by portal vein branch accurately.