Abstract: To investigate the significance of activation-induced cell death (AICD) in persistent infection of hepatitis virus B.The apoptosis of Peripheral lymphocytes (PBLs) isolated from patients with chronic hepatitis B and healthy blood donors was assayed by flow cytometer, and serum HBVDNA load was detected by real-time fluorescence PCR.According to HBVDNA quantity (copies/ml) , the patients with chronic hepatitis B (CHB) were divided into high (≥107/ml) , middle (105～106/ml) and low (<105/ml) virus load groups.The apoptosis ratio of resting PBLS in the three investigated groups was at low levels, there was no significant difference amone them (P>0.05) ;But compared with normal control, the percentage of apoptosis cells was significantly higher in the patients with chronic hepatitis B (P<0.01) and was lower in the patients with chronic severe hepatitis B (P<0.01) ;the percentage of apoptosis cells in the high virus load group was highest and that in the low virus group was lowest.The results suggest that activation-induced cell death of PBLs may play an important role in the pathogenesis of chronic hepatitis B and is aggravated with raise of virus load.