목적: To report the preliminary results of soft wall reconstruction and mastoid obliteration in canal wall down mastoidectomy (CWDM) to eliminate cavity problem 방법:The 12 patients who underwent CWDM with soft wall reconstruction and mastoid obliteration due to adhesive otitis media (From March 2014 to December 2014) or cholesteatoma were compared 13 patients who underwent canal wall up mastoidectomy due to chronic otitis media. The time of removal of a silastic drain, the duration of hospitalization and complication rate of the EAC skin were compared between two groups. <<Intervention>> After a retroauricular skin incision, an inferior based flap (IBF) was made. With no incision to the skin of the external auditory canal (EAC), the tympanomeatal flap was elevated. After harvest of bone paste from the cortical bone of the mastoid bone, CWDM was performed and then the pathologic lesion was taken out. The harvested deep temporalis fascia was attached into the defect of the skin of the EAC and the tympanic membrane with fibrin glue and pieces of gelfoam. The mastoid cavity and attic were obliterated with the harvested bone paste, which was fixed with fibrin glue. The mastoid tip and the space of the previous retrofacial air cells were obliterate with IBF. No meatoplasty and amputation of the mastoid tip were done. 결과:The time of removal of a silastic drain, duration of hospitalization and complication rate of the EAC skin were not statistically different between two groups (p=o.070, 0.946, 0.534 respectively). There was no serious complication like postoperative infection in CWDM with soft wall reconstruction and mastoid obliteration with bone paste. 결론:To avoid the disadvantages and get the advantages of CWDM, the procedures of soft wall reconstruction and mastoid obliteration were invented. Though this study has short follow-up period, it is thought that without complication, they could successfully prevent cavity problem and avoid frequent ear dressing, which were shortcomings of CWDM.