Abstract: Objective To investigate the prevalence of hepatocellular carcinoma（HCC）among first-degree relatives and explore the familial aggregation of HCC. Methods A cross-sectional study was performed on first-degree relatives of HCC probands treated at the Affiliated Cancer Hospital of Guangxi Medical University from 2004 to 2008.The binomial distribution model was applied to test the goodness-of-fit of the frequency distribution.Results There were 479 probands，accounting for 16.91%（479/2 832） of hospital admis-sions. Results of binominal distribution analysis showed that the number of HCC cases within proband families was significantly higher than the theoretical range（P=0.028）.The estimated separation ratio of HCC was 0.04，and the separation ratio variance was 0.000 015 09（SD=0.003 885，95%CI： 0.033 784～0.046 216）. Conclusion HCC shows significant familial aggregation in first-degree relatives of probands，and family history is one of the important risk factors for HCC. 

Key words: Liver neoplasms, Clinical epidemiology, Cross-sectional study, Binomial distribution