Nephrotic syndrome in children is primarily caused by minimal change disease. Majority of these patients respond well to corticosteroids. However, as many as 70% of children with nephrotic syndrome experience at least one relapse, and 30% develop a more complicated course with frequent relapses (FRNS)(≥2 relapses/ 6 months) with or without steroid dependency (SDNS)(relapse during tapering or within 2 weeks after discontinuation of corticosteroids). Repeated and prolonged courses of steroids in these children often result in long-term complications. The goal of the treatment is to reduce the rate of relapses, the cumulative dose of corticosteroids, and the incidence of serious complications. In order to minimize the side effects of steroid therapy, different steroid sparing agents such as cyclophosphamide, calcineurin inhibitors(CNI), levamisole, and mycophenolate mofetil (MMF) have been used in FRNS. Whereas CNI are usually considered the steroid sparing drug class of first choice, rituximab is increasingly used as alternative to minimize CNI toxicity. Various prospective studies suggest that Rituximab, a B cell depleting monoclonal antibody, could be a safe and effective alternative to steroid or immunosuppressants to achieve and maintain remission in this population.Single rituximab infusion have been shown to be efficacious for 6 to 12 months and the side effect profile observed to date is very benign. Studies comparing the usefulness of these agents are lacking. In our proposed randomized controlled trial, we want to compare the efficacy and safety of CNI to that of Rituximab in treating children with FRNS and SDNS.