OBJECTIVE To evaluate the bioequivalence and safety of two k inds of Nadroparin calcium injection in healthy Chinese volunteers by subcutaneous injection. METHODS According to the block randomization method ，24 Chinese healthy adult volunteers were included and divided into TR （test preparation-reference preparation ）group and RT （reference preparation-test preparation）group at a ratio of 1∶1. A randomized ，open-labelled，single-dose and two-cycle crossover study was designed ，the fasting subjects of two groups were given test or reference preparation 6 150 AⅩaIU subcutaneously on the first day of each cycle and exchanged in the second cycle ，and the wash-out period was 7 days. The blood samples were collected at different time points before and after administration. The activity of anti-coagulant factor Ⅹa（Anti-Ⅹa）and Anti- Ⅱa in human plasma were determined by chromogenic substrate method ，and the pharmacodynamic parameters were calculated according to the non-atrioventricular model and the bioequivalence was evaluated. The occurrence of adverse events （AEs）was recorded. RESULTS After administration ，the main pharmacodynamic parameters for Anti- Ⅹa activity of test preparation and reference preparation were as follows ：t1/2 were（4.87±1.06） and（4.03±1.00）h，tmax were 4.50（2.00，8.00）and 5.50（2.50，8.00）h，Anti-Ⅹamax were（0.66±0.12）and（0.56±0.11）IU/mL；main pharmacodynamic parameters of Anti- Ⅱa activity of two preparations were as follows ：t1/2 were（3.64±1.60）and（5.74±7.23）h，tmax were 4.00（2.50，8.00）and 4.00（2.00，8.00）h，Anti-Ⅱamax were both （0.10±0.03）IU/mL. The values of 90％confidence interval of geometric mean ratio of Anti- Ⅹamax，AUEC0－t and AUEC 0－∞ were 110.98％-123.50％，112.11％-121.24％and 111.57％-120.00％， respectively. During experiment ，14 subjects reported 19 cases of mild AEs ，among which hematoma ，purpura and maculopapular rash may be related to drugs ；no serious AEs were observed. CONCLUSIONS The domestic Nadroparin calcium injection is bioequivalent to the reference preparation ，and both of them show good safety.