Objective To study the significance of serum hepatitis B virus large envelope protein (HBV-LP),HBV DNA and HBeAg in the diagnosis of viral replication.Methods In 623 chronic HBV patients,HBV-LP and HBeAg were detected by ELISA and HBV DNA was quantitaively detected by realtime polymerase chain reaction(PCR).Results The positive rate of HBV-LP and HBV DNA were higher than that of HBeAg in all chronic HBV patients(x2 =22.3 and 9.4,P ＜0.01),and the positive rate of HBVLP and HBV DNA was no significant difference (x2 =2.8,P ＞ 0.05),The positive rate of HBV-LP and HBV DNA detected in HBeAg(+) or HBeAg(-) were not significantly different(x2 =3.2 and 0.6,P ＞ 0.05).HBV DNA copies and A vaule of HBV-LP was a positive correlation(r =0.874,P ＜0.01),HBV DNA copies of different groups was significantly different from HBV-LP A values(F =6.987,P ＜0.01).In 100 healthy people,the detecting results of HBV DNA and HBV-LP are negetive.Conclusion HBV-LP was better than HBeAg for detection of HBV replication.There is a good correlation between the copies of HBV DNA and the levels of HBV-LP,HBV-LP expression can reflect the replication of HBV.