Objective：To investigate the risk factors for hepatocellular carcinoma（HCC） combined with portal vein tumor thrombus（PVTT）. Methods：Retrospective analysis was conducted for 126 HCC patients chosen at random in the department of hepatobiliary surgery in the First Affiliated Hospital of Chongqing Medical Uni－versity from April 2009 to April 2011. Alpha-fetoprotein（AFP） level（400 ng/ml is the dividing line），with or without the PVTT，tumor size，cell differentiation grade（Edmondson-Steiner grade），tumor number，gender and vascular invasion were observed. Chi-square test and non-conditional logistic regression analysis were adopted to do statistical analysis. Results：Totally 126 patients were diagnosed as HCC including 56 HCC patients combined with PVTT（44.4%）. Vascular invasion，tumor size，high level of AFP，cell differentiation grade，tumor number were the risk factors for PVTT formation（χ2=20.97，13.67，4.73，5.04，all P<0.05）. Vascular invasion，tumor size，cell differentiation grade were the risk factors for AFP（χ2=8.121，4.038，all P＜0.05）. AFP and vascular invasion were the independent risk factors for PVTT. Conclusion：High leveled AFP could become one risk factor for HCC patients combined with PVTT，which can help to find or treat PVTT at early stage.