Background: Steroid Resistant Nephrotic Syndrome is a disease which can cause massive proteinuria. In the furtherer study, this condition leads to hypocalcemia and hypoalbuminemia which can cause hyponatremia. Gabus extract capsules supplementation is expected to prevent tetani because of hyponatremia and to correct hypocalcemia in children with Steroid Resistant Nephrotic Syndrome.Aim: Proving the effect of gabus extract capsules supplementation 2x500 mg for 21 days toward the increase of natrium and calcium serum levels in children with Steroid Resistant Nephrotic Syndrome aged 2-18 years.Method: This study used quasi experimental pre and post test design. The respondents are children with Steroid Resistant Nephrotic Syndrome who came into the clinic of RSUP dr. Kariadi Semarang in May 2015, have the inclusion criteria and agreed to received gabus extract capsules supplementation 2x500 mg. This study was done for 21 days.Result: The mean changes of natrium serum level is 1,71 + 0,31 mmol/L. The mean changes of calcium serum level is 0,028 + 0,11 mg/dL. There were no significant differences in changes of natrium serum level (p = 0,308) and changes of calcium serum level (p = 0.905) using paired t-test.Conclusion: Gabus extract capsules supplementation at a dose of 2x500 mg for 21 days did not significantly increasing the levels of natrium and calcium serum of child with Steroid Resistant Nephrotic Syndrome.