Degree of portal vein involvement is fairly reliable in predicting longterm survival. And tumor thrombus in the trunk of protal vein has been considered contraindication for liver resection and transcater arterial chemoembolization(TAE). At recent as development of operative technique of liver, cumulative experience of operation and development of ability to pre- and post-operative management of metabolism of liver, aggressive surgical resection has been applied to these patient group that has tumor thrombi in main protal vein by some surgeon. Tumor thrombus in the trunk of the portal vein has been considered dotraindication for liver resection. However, the negative results of conservative therapy have encouraged us to remove the tumor. We performed right lobectomy successfully for the hapatocellular carcinoma(HCC) with tumor thrombus in the first order branch of portal vein and the patient is alive for 37 months without recurrence. In conclusion the aggressive surgical approach for the HCC presenting with tumor throumbus in right first order branch of portal vein should be considered for long term survival.