Background Cyclosporine A (CsA) has been widely used in the treatment of aplastic anemia (AA),but the application of CsA was limited in patients who had liver diseases or abnormal liver function due to its liver toxicity.Glycyrrhizin has long been used in China in the treatment of various liver diseases to lower transaminases.In this study,we observed the efficacy and safety of glycyrrhizic acid combined with CsA in the treatment of newly diagnosed patients with non-severe AA (NSAA).Methods A total number of 76 patients with newly diagnosed NSAA were enrolled into the study at our hospital between July 2005 and June 2010.The patients were divided randomly into two groups:the glycyrrhizin-treatment group (group A) and the control group (group B) with 38 patients in each group.All patients received 3-5 mg·kgl.d-1 CsA for at least 4 months and were treated either with or without glycyrrhizin for 4 months.Results sixty-eight patients were eligible for evaluation.In the control group,9.09％ patients (n=3) achieved a complete response while 51.52％ (n=17) attained a partial response.The overall response rate was 60.61％ (n=20).The remaining 13 patients (39.39％) did not have any response.In the glycyrrhizin-treatment group,complete response rate was 20％(n=7) and partial response rate was 62.86％ (n=22).The overall response rate was 82.86％ (n=29) and the non-response rate was 17.14％ (n=6).Response rate was significantly increased with the addition of glycyrrhizin to CsA compared with CsA alone (P＜0.05).Conclusion The combination of glycyrrhizin and cyclosporine regimen was an effective treatment for NSAA in terms of improvement of response rate,reduction in CsA-related liver injury,and attenuation of sevedty of nausea and other adverse events in the treatment of patients with NSAA.