The aim of this study was to investigate the bcl-2/IgH expression levels in patients with follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL) and its clinical significance. The bcl-2/IgH expression levels in bone marrow (BM) and/or peripheral blood (PB) of 20 patients were detected by using SYBR Green I real-time polymerase chain reaction, and the dynamic monitoring for bcl-2/IgH expression level in 4 of these patients was performed. The results showed that in patients with bcl-2/IgH-positive there was no statistically significant difference in the relative copy-numbers of bcl-2/IgH fusion gene in BM and PB (4.23 and 2.73 respectively, p = 0.107), but the difference was significant before and after treatment (3.61 and 2.69 respectively, p = 0.000), the expression level of bcl-2/IgH fusion gene in newly diagnosed and relapsed group was remarkably higher than that in remission group (p = 0.008). The bcl-2/IgH expression level in PB increased evidently 3 months prior to the clinical relapse in one case out of dynamically monitored 4 cases. It is concluded that the bcl-2/IgH expression level is associated with the disease status, the expression level is high in newly diagnosed and relapsed patients and low in those who achieved remission, the bcl-2/IgH fusion gene expression level decreased evidently after therapy, this change may be related to the clinical disease progression, the results suggest that peripheral blood can be regarded as the resource for detection of bcl-2/IgH fusion gene.