Abstract: Objective To study the relationship between familial chronic hepatitis B virus(HBV) infection and human leucocyte antigen(HLA-Ⅱ) class gene polymorphism.Methods HLA-DQA1 and DQB1 allele polym orphism was ana lyzed among persons with and without chronic HBV infection in 37 familie swith 121 persons of chronic HBV infection and 76 persons of HBsAg-negative with PCR/SSP.Peripheral blood mononuclear cells were cultured in the medium to induce dendritic cell(DC)and mixd lymphocyte reaction was adopted to detect the capacity of DC for stmiulating lymphocyte pro liferation.Results The allele frequencies of HLA-DQA1 0501 and DQB1 0301,DQB1 0201 in patients with chronic HBV infection were significantly higher than those of HBsAg-negative group.HLA-DQB1 0402 and DQB1 0604 allele frequency of the patients was significantly lower than that of HBsAg-negative group.The lymphocyte proliferation index stmiulation in dex(SI) in HLA-DQA1 0501,DQB1 0301 positive group was significantly lower than that of negative group(P < 0.01) and HLA-DQB1 0402 and DQB1 0604 in positive group was significantly higher than that in the negative group.Conclusion Familial chronic HBV infection is closely associated with HLA-DQA1 and DQB1 gene polymorphism.HLA-ògenes can affect the DC capacity to stmiulate lymphocyte proliferation and play a role in mimune regulation,and may be related to chronic infection of the HBV.