OBJECTIVE It has been recognized that HBV infection and alcohol consumption are two important risk factors for primary hepatocellular carcinoma(HCC).Recently,the role of clonorchiasis as a risk factor for HCC is controversial.We aimed to investigate whether these factors increase the risk of HCC in Guangxi,China.METHODS A hospital-based,case-control study of HCC was conducted from July 2005 to July 2007.We enrolled 500consecutive patients with HCC as an experimental group and 500patients without tumor in liver as a control group.nle risk factors that the patients were exposed to were assessed.RESULTS Comparing the risks of developing the HCC,we found out the following results.The risk of developing HCC for the patients with clonorchiasis was 5 folds of that for the patients without clonorchiasis(OR=5.0;95%CI:3.1-8.1),and the risk for the patients with alcohol consumption was 3 folds of that for the patients without drinking alcohol(OR=3.4;95%CI:2.3-4.9),and similarly,the risk for the patients with HBV infection was 21 times of that for the patients without HBV infection (OR=20.6;95% CI:14.3-29.7).According to crossover analysis,there was significant interaction among clonorchiasis,HBV infection and alcohol consumption,with synergistic indices greater than 1.The etiologic fractions attributed to these interactions [EF(A x B)] are 0.7465,0.5789 and 0.5506,respectively.CoNCLUSION Clonorchiasis,HBV infection and heavy alcohol consumption are independent risk factors for developing HCC in our population in Guangxi,and as they can interact synergistically,the risk of developing HCC is increased.Data from this study may indicate new prevention strategies of developing HCC in hish-risk individuals.