AIM: To appraise the bioequivalence and safety of the test preparation of ritonavir tablets and the reference preparation (trade name: Norvir?) in healthy adult subjects under fasting and postprandial conditions. METHODS: This study was a randomized, open-label, single-dose, four-period, fully repeated crossover design bioequivalence study protocol. Thirty-six healthy male and female volunteers were enrolled in the fasting and postprandial conditions, and a single dose of the test preparation and reference preparation was orally administered. We used liquid chromatography-tandem mass spectrometry (LC-MS/MS) to finish the bioassay of the drug concentration of ritonavir in plasma. Pharmacokinetic parameters were statistically analyzed using PhoenixWinNonlin8.1 software (Pharsight, USA) and a non-compartmental model.RESULTS: Under fasting conditions, the pharmacokinetic parameters of the test and reference preparations: Cmax (792.010±369.282) ng/mL and (856.939±394.427) ng/mL, AUC0-t (6 463.043±2 876.849) ng·mL-1·h and (6 907.690±3 046.132) ng·mL-1·h, AUC0-∞(6 603.617±2 916.352) ng·mL-1·h and (7 051.614±3 093.047) ng·mL-1·h. Here are the pharmacokinetic parameters for both the test preparation and the reference preparation in the postprandial condition: Cmax (574.380±289.566) ng/mL and (615.796±297.382) ng/mL, AUC0-t (5 084.796±2 435.557) ng·mL-1·h and (5 414.167±2 416.952) ng·mL-1·h，AUC0-∞ (5 219.144±2 487.793) ng·mL-1·h and (5 551.060±2 490.604) ng·mL-1·h. The 90% confidence interval of the geometric mean ratio of AUC0-t, AUC0-∞, and Cmax for the test preparation and reference preparation lied in the equivalent range of statistics. CONCLUSION: The tested preparation was bioequivalent to the reference preparation under fasting and postprandial conditions.