Abstract: Objective To analyze the therapeutic effect of plasma exchange combined with Lamivudine in severe chronic hepatitis B patients.Methods Patients in the treatment group were given the plasma exchange therapy combined with Lamivudine and basic medical treatment, whereas patients in the control group were given only lamivudine along with the same basic medical treatment.Results Liver function of the treatment group patients were significantly improved, with the decrease of levels of ALT and SB, while increase of CHE and PTA significantly (P < 0.05) .Quantities of HBV DNA between two groups showed significant differences (χ2 = 6.95, P < 0.01) .The gross effective rate of the treatment group was higher than the control group significantly (χ2 = 4.13, P < 0.05) and the mortality rate between two groups were significantly different (χ2 = 4.57, P < 0.05) .Conclusion Early plasma exchange combined with Lamivudine could effectively inhibit virus replication and rapidly remove toxins in CHB patients.Combined therapy could ameliorate patient's condition and decrease the mortality.