OBJECTIVE:To explore the correlation between ornidazole (ONZ) salivary concentration and plasma concentra-tions in healthy subjects,and to provide reference for clinical therapeutic drug monitoring. METHODS:24 healthy volunteers were selected. After oral administration of ONZ capsules 1.00 g,their venous blood and saliva were collected at 0.25,0.5,1.5,5.5, 10.5,24.5 and 43.5 h after medication. HPLC method was used to determine the plasma and salivary concentrations of ONZ. The correlation between the two was analyzed. RESULTS:The peak values of plasma and salivary ONZ concentrations appeared imme-diately at 1.5 h after administration and the peak values were(0.96±0.15)μg/ml and(0.93±0.15)μg/ml;salivary concentration of ONZ was lower than plasma concentration at each time points,but there was no statistical significance (P>0.05);the regres-sion equation of salivary ONZ concentration and plasma concentration was csaliva=1.176 5cplasma-0.199 4(r=0.990 1). The ratio of salivary concentration and plasma concentration of ONZ (S/P) was (0.91 ± 0.06),showing positive correlation (r=0.632-0.970, P<0.05). CONCLUSIONS:The salivary ONZ concentration is significantly correlated with plasma concentration in healthy peo-ple,so saliva can be used for therapeutic drug monitoring.