Objective:To explore the clinical efficacy of transcanal endoscopic ear surgery in the diagnosis and treatment of conductive hearing loss with intact tympanic membrane. Method:The clinical data of 16 patients with conductive hearing loss with intact tympanic membrane were retrospectively analyzed. They were diagnosed and treated by transcanal endoscopic ear surgery. Result:All patients were diagnosed by exploratory tympanotomy, including 6 cases of congenital middle ear anomalies, 5 cases of congenital cholesteatoma, 2 cases of congenital middle ear anomalies with congenital cholesteatoma, 2 cases of otosclerosis, and 1 case of traumatic ossicular chain disruption. During the tympanic exploration by transcanal endoscopic ear surgery, different methods of hearing reconstruction were applied according to the intraoperative lesions. Among 14 cases(14 ears), 7 patients underwent reconstruction with partial ossicular replacement prosthesis (PORP), 5 patients had total ossicular replacement prosthesis (TORP), and 2 patients had piston. The remaining 2 patients did not undergot ossicular reconstruction. After the operation, the mean air-conductive threshold of 14 patients decreased from (61.7±6.5) dB HL to (29.8±10.7) dB HL (P<0.01) and the mean ABG decreased from(36.8±3.2) dB HL to (10.7±6.9) dB HL (P<0.01). 1 case of congenital middle ear anomalies with congenital cholesteatoma underwent the lesion resection without ossicular reconstruction. Due to lack of suitable Piston, 1 case of congenital middle ear anomalies with fixed stapes did not perform hearing reconstruction. No serious complications occured after operations. Conclusion:Transcanal endoscopic ear surgery was suitable for the diagnosis and treatment of conductive hearing loss with intact tympanic membrane. It was minimally invasive with low complications, and the patients had a good hearing recovery after ossicular reconstruction.