Objective To evaluate the efficacy of 5fluorouracil (5-Fu) in treatment of laryngotracheal stenosis in rabbit models. Methods Tracheal menbrane of 20 New Zealand rabbits was scraped about 0.5cm with a nylon brush to induce scar formation, and then randomly divided into 2 groups: 5Fu group and saline group. Intralesional 5Fu injection by tracheal puncture was given for seven days after surgery. The stenosis degree was observed under laryngofiberoscope at days 4, 8, 12, 16, 20, 24 after administration. The day of administration as day 0, survival of animals was monitored. A survival curve was obtained by the KaplanMeier method and analyzed by the logrank test.Results Survival time in the 5Fu group was significantly prolonged compared to that in the control group (P=0.0128). Histologic photomicrographs of 5Fu group showed that granulation tissue formation was rarely seen in the scraped lesion. The remain granulation tissue was patchy in distribution over the lesion. Most of the patchy granulations were located in deep layer of the tracheal rather than in superficial layer. Howener, in the control group dense granulation tissue composed of proliferating fibroblasts and thickened collagen fibers was seen in the scraped lesions. Conclusion 5-Fu can prevent airway stenosis in rabbit models.