Abstract： Objective To identify the changes in serum insulin like growth factor-Ⅰ (IGF-Ⅰ) and IGF binding proteins (IGFBPs) in children with nephrotic syndrome (NS) and the effect of glucocorticoid on serum IGF-Ⅰ and IGFBPs. Methods We measured serum IGF-Ⅰ and IGFBPs levels by radioimmune assay and immune radiomagnetic assay in 36 children with NS, consisting of an active stage group (ANS, n=12), a remission stage group (RE, n=12), an active stage group with glucocorticoid treatment (GNS, n=12), and a normal control group (NC, n=10). Results 1) Compared to NC, serum levels of IGF-Ⅰ and IGFBP-3 were decreased (P<0.01); serum levels of IGFBP-1 and IGFBP-2 were increased (P<0.01) in the ANS group. 2) Serum levels of IGF-Ⅰ and IGFBP-3 were higher and IGFBP-1 and IGFBP-2 were lower in the RE Group than in theANS Group (P<0.01). 3) Compared to the ANS group, serum levels of IGF-Ⅰ and IGFBP-3 were increased (P<0.01) and serum levels of IGFBP-1 and IGFBP-2 were decreased (P<0.01) in the GNS group. 4) A correlation was found between serum levels of IGFBP-3 and albumin in the active stage group (r=0.76, P<0.01). There was also a correlation between serum levels of IGF-Ⅰ and IGFBP-3 and an inverse correlation between the serum level of IGF-Ⅰ and serum levels of IGFBP-1 and IGFBP-2 in the ANS group. No other correlations were observed. Conclusions The serum levels of IGF-Ⅰ and IGFBPs are altered in children in the active stage of NS, but return to normal in the remission stage. GC treatment may influence serum IGF-Ⅰ and IGFBPs in children with NS. Changes in IGF-Ⅰ and IGFBPs levels may play a role in the growth retardation of NS children.