OBJECTIVE: To investigate the effect of low-dose hepacarin in the treatment of the primary nephrotic syndrome in children. METHODS: Eighty two children with the primary nephrotic syndrome in the hypercoagulable state were studied prospectively. All the patients were administrated with prednisone 2 mg/kg·d (maximum dose ≤ 60 mg/d). Fifty two of them, besides prednisone, were administrated with hepacarin (50 IU/kg·d, intravenous injection for 4 weeks), who formed the treatment group. The other 30 belonged to the control group. RESULTS: There was no significant difference in remission (negative proteinuria) between the treatment group and the control group (P> 0.05 ). The time taken for remission was shorter in the treatment group [( 13.08 ± 4.75 ) d] than that in the control group [( 19.33 ± 4.48 ) d] (P< 0.01 ), so was the initial diuresis time [( 9.64 ± 2.65 ) d vs ( 17.07 ± 3.99 ) d](P< 0.01 ). The plasma fibrinogen recovery efficiency in the treatment group ( 93.3% ) was significantly higher than that in the control group ( 65.4% ) (P< 0.05 ). However, no significant difference in the urinary FDP recovery efficiency was found between the two groups. CONCLUSIONS: Low dose hepacarin had an obvious anticoagulation effect. Although it can not improve the remission rate of urinary protein in the treatment of the primary nephrotic syndrome in children, it can shorten the induced remission time and enhance diuresis effects.