Objective: To understand the quantity and distribution of CD83 + mature dendritic cells in patients with hepatitis B virus in immune tolerant phase. Methods: There were 30 immune tolerant phase patients with hepatitis B virus infection (fibrosis stages were S0), 10 immune clerance phase patients, 10 non-active status patients and 5 healthy controls involved in our research. The quantity and distribution of CD83 + mature dendritic cells in liver were determined by immunohistochemical staining. Result: The liver inflammation grades were between G1-G2 in patients who in inmmune tolerant phase and non-active status, moreover, patients in immune clerance phase were between G2-G4. There were a small amount of CD83 + dendritic cells in healthy liver tissue, scattered in portal areas and hepatic lobules. The quantity and distribution of CD83 + dendritic cells in patients who in inmmune tolerant phase and non-active status were similar to the healthy, and the quantity were no difference among them p 0.05 .The number of CD83 + cells in patients of immune clerance phase was significant increased compared with other groups, there were differences among them p 0.05 , the CD83 + cells mainly distributed in portal areas infiltrated with inflammatory cells and hepatic lobules with inflammatory necrosis. Conclusion: CD83 + mature dendritic cells are involved in liver immune response in patients of inmmune clerance phase, is likely to related to hepatitis B virus clearance. Lack sufficient mature dendritic cells may be one of the mechanisms of immune tolerance. Background: Local hospitals provide obstetric services including antenatal care to women normally living in the Mainland China, whose prevalence of hepatitis B carrier is unknown. Objectives: Compare prevalence of HBV carrier of pregnant women from the Mainland China with local counterparts and discuss the implications of results. Materials and Methods: Antenatal serological results were retrieved from corporate laboratory information system databases. Pregnant women from the Mainland China were identified by a specific set of temporary-allocated identity number during January 2007 -October 2008. Results: 7491 pregnant local residents and 1397 pregnant women from the Mainland China underwent antenatal serological tests for hepatitis B surface antigen. Positive hepatitis B surface antigen results were more frequent in pregnant women from the Mainland China (12.7%) than in local pregnant women (8.17%) (p<0.001). Discussion: Because infected pregnant women can transmit the hepatitis B virus to the infant at delivery, specific management could entail maternal medication, injection of hepatitis B immune globulin to the infant at birth and immunization later on. However, early repatriation to the Mainland China, which is common, will make completion of immunization program difficult. These babies will be at a higher risk to be infected by HBV, particularly when breast-fed by HBV carriers. Their return to Hong Kong later will dilute the effects of local immunization program. The volume of work derived from the provision of obstetric services to women from the Mainland Chinese is larger with regard to medication, counseling and immunization for babies born to HBV carriers.