Objectives:To evaluate the analgesic effects and safety of tinidazole in the prevention and treatment of alveolalgia. Methods:Tinidazole was used in 600 patients after the extraction of impacted tooth as the test group for the prevention of alveolalgia, and metronidazole was used in other 600 patients as the control group. The clinical and laboratory tests were carried out before and after the treatment. And the MIC of tinidazole and metronidazole were determined in samples of positive anaerobic cultures. Results:Twenty eight patients with alveolalgia were treated. It showed that it was significantly more effective in the test group than that in the control group. The MIC of the tinidazole group, however, was not different from that of the metronidazole group( P 0.05).There was also little side effects from the use of tinidazole. Conclusions:Tinidazole is an effective and safe antianaerobic medicine and can be used to replace metronidazole.