In this study, efficacy and safety of two different dosages of rabbit antithymocyte globulin (r-ATG) combined with cyclosporine (CsA) in treating children with severe aplastic anemia (SAA) were compared. The clinical data of 122 SAA children treated by r-ATG/CsA between Jan 2005 and Jan 2017 at Sun Yat-sen Memorial Hospital of Sun Yat-sen University were retrospectively analyzed. The r-ATG dose of 55 cases was 2.5mg/(kg·d, group 1), and in the other 67 cases it was 3.5 mg/(kg·d, group 2). r-ATG was continuously administered for 5 days. In the 3rd and 6th month after treatment, the efficacy rate of group 2 was higher than that of group 1 (45.5% vs 26.4%, P=0.032; 54.5% vs 35.8%, P=0.042). In the 9th and 12th month after treatment, the efficacy rates of both groups were similar (71.2% vs 54.9%, P=0.077; 75.9% vs 68.6%, P=0.399). The incidence rates of serum diseases (74.5% vs 79.1%, P=0.551), short-term infection rates (76.4% vs 62.7%, P=0.105), early mortality (3.6% vs 1.5%, P=0.447), and 3-year overall survival rates (89.5% vs 90.1%, P=0.932) of both groups showed no significant differences. The r-ATG/CSA therapy was safe and effective towards SAA. The final efficacies and safety of the two r-ATG dosages were equal. However, the follow-up period in this study was relatively short, so the intergroup comparison of the long-term complications and survival rates needed to be further followed up.