To study the characteristics of EBV transformed human peripheral blood B cell lines from hepatitis B patients and to provide a basis for further studies on the cellular immune function of hepatitis B patients.High titer of EBV was produced by B95 8 cell by induction with sodium n butyrate,and peripheral mononuclear cells from two different groups of hepatitis B patients were harvested and infected with EBV. The results showed that 4～8 weeks after infection 19 EBV transformed B cell lines from hepatitis B patients were established. It was found that colony formation of cells from A group appeared 2～3 weeks later than B group. Cells grew healthily and had good activity after 4 weeks of freezing.CD19 and CD20 were detected in 88 34% and 37 48% of the immortalized B cell membrane respectively. HBV DNA could not be detected in a11 19 immortalized B cell lines.It suggested that the time needed for the establishment of B cell lines was related with the immune state of the patients.HBV DNA could not exist persistently, and it would disappear finally in the immortalized B cell lines.