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