Objective The aim was to analyze the clinical effects of subtotal petrosectomy for lesions of lateral skull base. Methods The clinical datas of 78 patients who received subtotal petrosectomy from July 2007 to September 2019 were retrospectively collected: 40 males and 38 females, with an average age of 37.3±14.1 years. There were 28 cases of petrous bone cholesteatoma, 20 cases of chronic otitis media reinfection, 19 cases of temporal benign tumor and 11 cases of cerebrospinal fluid otorrhea. All patients underwent pure tone audiometry, CT of temporal bone, MRI of inner ear and facial nerve function evaluation before the surgery.Preoperative facial nerve function in Grades according to House-Brackmann (HB) were：grade I in 25 , grade II in 19 , grade III in 15 , grade IV in 10 , grade V in 5 and grade VI in 4 .There were 21 cases of total deafness on the affected side before operation, and the average hearing of the other patients was 52.2dB.CT of temporal bone and MRI of inner ear were followed up and the function of facial nerve was evaluated after surgery. Results Patients were followed up for an average of 5.51 years.All 78 patients successfully completed surgery,and there were no deaths and no severe complications such as intracranial hemorrhage, or cerebrospinal fluid otorrhea. 2 patients with petrous bone cholesteatoma and 2 patients with chronic otitis media reinfection recurred after surgery and were cured by repeated operation. All the 19 patients with temporal benign tumors underwent total resection during the operation, and 9 of the 14 patients with facial schwannoma underwent facial nerve - hypoglossal nerve anastomosis.Postoperative evaluation of facial nerve function (House-Brackmann scale) was as follows: Grade Ⅰ in 28 , grade Ⅱ in 20, grade Ⅲ in 17, grade Ⅳ in 7, grade V in 2 and grade Ⅵ in 4.In all patients, functional hearing was not retained on the affected side after surgery. Conclusion Subtotal petrosectomy is suitable for extensive resection of petrous bone cholestatoma, chronic otitis media reinfection and temporal benign tumors, and it can also be used to repair and prevent cerebrospinal fluid otorrhea.Since this procedure cannot preserve or reconstruct hearing, it is suitable for patients with extensive skull base lesions and no conditions for hearing reconstruction.