Objective To analyze serum levels of C1q in children with nephrotic syndrome (NS),and investigate the clinical significance and the relationship among the altered serum C1q levels and other lipid/lipoprotein and renal function parametersin children with NS inacute and remission phases.Methods Serum levels of C1q were measured in 78 NS children with acute phase,in 64NS children with remission and in 77 healthy control children.The other lipid/lipoprotein and renal function parameters were also analyzed in these children,including TP,ALB,TC,TG,LDL-C,HDL-C,Urea,Cr and Uric.Results Compared with the healthy control children [173.00(161.00～185.00)mg/L],children with NS inacute [203.50(183.75 ～ 223.75) mg/L] and remission phases [185.00 (161.00 ～ 202.00) mg/L] all had a significantly increasedserum levels of C1q.Compared with NS children in remission,those in acute phase showed a significantly increased C1q (P＜0.001).In all the NS children,the serum levels of C1q were positively correlated with the levels of TC (r=0.483,P＜0.001),TG (r=0.423,P＜0.001) and LDL-C (r=0.450,P＜0.001),while negatively correlated with the levels of TP (r=-0.276,P=0.001 ＜0.01) and ALB (r=-0.410,P＜0.001).Multiple linear regression analyses showed that serum levels of C1q were independently associated with serum TG levels (β=9.235,P＜0.001;adjusted R2 =0.215) after adjustment of other related factors.Conclusion Serum levels of C1q were significantly increased in NS children in association with their conditions and the levels of lipid/lipoprotein parameters,and may be function as anovel parameter for assessing the development of NS.