Abstract: Objective To explore the risk factors of primary nephritic syndrome complicated with thrombosis in children. Methods Clinical data of 238 children with primary nephritic syndrome were retrospectively analyzed. The children were divided into thrombosis group and non-thrombosis group according to whether complicated with thromboembolism. Univariate and logistic regression analysis were performed. Results Among 238 children, there were 32 cases of primary nephritic syndrome complicated with thrombosis and the rate was 13.44%. Univariate analysis showed that infections, the use of diuretic, degree of edema, white blood cell count, IgG, C3, total protein, albumin, urea nitrogen, plasma fibrinogen, D-dimer, antithrombin Ⅲ, and 24-hour proteinuria were significantly different between two groups (all P ＜ 0.05). Multivariate analysis showed that D-dimer and 24-hour proteinuria were the independent risk factors for children with primary nephrotic syndrome complicated with thrombosis. Conclusion The elvated level of D-dimer and 24-hour proteinuria were the risk factors of children with primary nephrotic syndrome complicated with thrombosis.