Immunosuppressive therapy (IST) with antithymocyte globulin (ATG) and cyclosporine (CsA) is the standard treatment for children with severe aplastic anemia (SAA) with no human leukocyte antigen-matched siblings. Due to the unavailability of horse ATG in China, porcine antilymphocyte globulin (p-ALG), which is less expensive and more effective than rabbit ATG, is widely used. We sought to evaluate the efficacy and safety profile of modified IST with p-ALG plus delayed CsA at day 21 in 50 SAA children. Eighteen SAA patients who progressed from nonsevere aplastic anemia (NSAA) were classified as SAA-II; the other 32 patients were classified as SAA-I. Overall response (OR) rates at 3, 6 and 12months were 56, 64 and 62%, respectively. The 10-year overall survival (OS) rate and disease-free survival (DFS) rate were 80 and 56%. The OR, OS and DFS rates in the SAA-I group were clearly better than those in the SAA-II group. Death rate from infection within 30days was 4%. Modified IST with p-ALG plus delayed CsA is a reliable and well-tolerated treatment for children with SAA, and reduces early death due to infection. Modified IST is more suitable for children with SAA-I.