Abstract: Objective TO evaluate the clinical effect of treatment of choanal atresia after radiotherapy in the patients with nasopharyngeal carcinoma by transnasal endoscopic surgery. Methods 8 cases of choanal atresia after radiotherapy were operated by the way through palate,seting tube to nasal cavity after operation.30 cases were operated under endoscopic surgery but not to set tube. Results 36 cases were cured.2 cases were fail with nasal adhesion. Conclusion Endoscopic surgery is the best way to treat choana...