To investigate the surgical approach, techniques and clinical efficacy ofdacryocystorhinostomy under nasal endoscope in treating chronic dacryocystitis. METHODS:Thirty-eight cases (40 eyes)with chronic dacryocystitis were treated with endoscopic transnasal dacryocystorhinostomy and were rinsed the lacrimal passage and nasal cavity routinely under nasal endoscope after operation. RESULTS:After 5-14 months follow-up, the stoma inside nasal cavity of 35 patients (37 eyes)were unobstructed, the symptoms of pyorrhea and epiphora disappeared; the symptoms of pyorrhea and epiphora occured in 2 eyes 3 months after operation, the stoma inside nasal cavity were obstructed, and the stoma was expanded again under nasal endoscope, 1 case was cured, 1 case was invalid;1 eye was obstructed with rinses overflowing and needed pressurizing. The total effective rate was 95% (38/40). CONCLUSION:Endoscopic transnasal dacryocystorhinostomy has advantanges of less damage,no facial scar,easy to operate and so on.Intraoperative fine operation and strengthening follow-up after surgery are the important conditions for therapeutic effect. Endoscopic transnasal dacryocystorhinostomy is effective in the treatment of chronic dacryocystitis and worthy of clinical promotion and application.