The effects of plasma endothelin-1 (ET-1) and aldosterone (Ald) on sodium retention in children with nephrotic syndrome were investigated. 14 cases were divided into the edematous stage and non-edematous stage. Plasma ET-1, Ald, and serum osmolarity, albumin (Alb), and Na+ were measured in each stage. The results showed that the plasma ET-1 in edemaous stage increased significantly, compared with that in no-edematous stage (P < 0.01). There was no significant difference in plasma Ald between the edematous stage and the non-edematous stage. Plasma ET-1 was positively correlated with the serum sodium ionic concentration and negatively correlated with the serum Alb(r = 0.486, P < 0.01; r = 0.490, P < 0.01, respectively). In conclusion, the sodium retention with nephrotic syndrome might be correlated with reduction of secreted sodium in the kidney, suggesting that ET-1 plays an important role in pathogenesis.