Objective:CHOP is the standard regimen to treat diffuse large B cell lymphoma (DLBCL). With the anti-CD20 monoclonal antibody (rituximab,R) combined with CHOP regimen,the therapeutic effect of R-CHOP regimen is further improved. To investigate the clinical significances of treatment-related variables for the diffuse large B-cell lymphoma (DLBCL) patients who treated with front-line (R)-CHOP regimen. Methods:This retrospective study evaluated 52 conservative newly diagnosed patients who were treated with (R)-CHOP regimen. The prognostic roles of international prognostic index (IPI),average dose intensity per cycle (DIPC) and dose intensity per week (DIPW) of cyclophosphamide,doxorubicin,prednisone in (R)-CHOP regimen were evaluated. Results:The median follow-up period of this study was 34 months(from 6 to 95 months). Pearson Chi-Square analysis showed that complete response (CR) rates were significantly affected by average DIPW of prednisone <166.7 mg/m2,IPI scores and Ann Arbor stage (A or B group) (all P < 0.05). When the two factors were subsequently tested by multifactorial Logistic stepwise regression,average DIPW of prednisone <166.7 mg/m2 and IPI scores were again showed to be independent risk factors for CR rate. With regards to OS,it was showed to be significantly affected by IPI scores,average DIPW of cyclophosphamide <250 mg/m2 and doxorubicin <16.7 mg/m2 (all P < 0.05). In the subsequent Cox regression test,only IPI scores and average DIPW of doxorubicin <16.7 mg/m2 were showed to be independent prognostic factor for OS rate. Conclusion:In addition to IPI scores and Anna Arbor stage (A or B group),average DIPW of doxorubicin was also showed to be an important prognostic factor for the clinical outcome of newly diagnosed DLBCL patients who were first-line treated with (R)-CHOP regimen. It is strongly recommended to strictly adhere to planned (R)-CHOP regimen schedule in every possibility.