Objective:To investigate the expression of bcl-2 on the effect of rituximab in patients with different subtypes of diffuse large B cell lymphoma (DLBCL).Methods:Night-six DLBCL patients were divided into chemotherapy group (60 cases) and immune chemotherapy group (36 cases,rituximab plus chemotherapy).According to the pathological results,the patients were divided into the germinal center type (GCB type) and the non germinal center type (N-GCB type),bcl-2 protein expression positive and negative subgroup. The 3 years survival rate of the patients were analyzed.Results:The 3 years survival rate (77.78%) of the immune chemotherapy group was higher than in the chemotherapy group (60.00%),but the difference was not statistically significant (P>0.05).The median survival time of patients with GCB in immune chemotherapy group was longer than N-GCB patients,and also was longer than patients with GCB or N-GCB in chemotherapy group (all P<0.05).Median median survival time of patients with N-GCB in immune chemotherapy group and patients with GCB in chemotherapy group were longer than patients with N-GCB in chemotherapy group (all P<0.05).The median survival time of patients with bcl-2 negative was longer than patients with bcl-2 positive in immune chemotherapy group,and also was longer than patients with bcl-2 positive or negative patients in chemotherapy group.The median survival time of patients with negative bcl-2 was longer than patients with bcl-2 positive patients in chemotherapy group(all P<0.05) and was also longer than patients with bcl-2 positive(P<0.05) in immune chemotherapy group.Conclusion:Rituximab can significantly prolong survival time of patients with DLBCL,particularly to patients with N-GCB or bcl-2 positive.