목적: This study was designed to assess the usefulness of the secondary mastoid obliteration(term used as mastoid elevation) using autologous costal cartilage to overcome the cavity problem after canal wall down tympanomastoidectomy. In this report, we compare the preoperative and postoperative stability of external auditory canal. 방법:Patients with cavity problem after canal wall down tympanomastoidectomy were analyzed retrospectively at Chonnam National University Hospital from September 2012 to January 2015. The patients underwent mastoid elevation postoperatively to eliminate the cavity problem using autologous costal cartilage. The preoperative and postoperative finding of external auditory canal were checked. 결과:Total 12 patients underwent secondary mastoid obliteration using autologous costal cartilage. This group consisted of 4 male and 8 female patients. The mean age was 46.8435.35(range15~65 yrs). These cases consisted of 3 cases with adhesive OM, 4 cases with chronic otitis media and 5cases of cholesteatoma. One patient with cholesteatoma, who underwent canal wall down tympanomastoidectomy and mastoid obliteration using bone pate and periosteal flap previously showed cavity problem postoperatively. After mastoid elevation, the postoperative canal wall stability was improved on TBCT and endoscopic finding. The rest of the 11 patients did not undergo mastoid obliteration on primary operation.Only 3 patients suffered from otorrhea as complications. The rest 9 patients showed intact external auditory canal wall postoperatively, and no complications were found. 결론:There are many disadvantages for the patients with open cavity state after canal wall down tympanomastoidectomy, and using costal cartilage is an effective surgical choice for the mastoid elevation.