Vicagrel (compound 9a) (oral, 3 mg/kg) has inhibitory effect on ADP-induced platelet aggregation in rats. Vicagrel (oral, 1.14 mg/mL, 0-24 h) has giood preliminary pharmacokinetic with high bioavailability and low clinically effective dose. Vicagrel (oral, 5 g/kg, single, for 14 days) has low dose-related toxicity in mouse.