Since Massaro and Gonnering's discription of endoscopic laser dacryocystorhinostomy (DCR) that opening at lateral nasal wall is made by endonasal approach in 1989, endoscopic laser DCR has been undergone in Korea since 1992. During recent two years sixty-nine cases of endoscopic laser DCR were performed at our institute. Of these procedures, a retrospective chart review of 16 patients extubated silicone tube was performed for the study of the association between failure and either the size of opening or duration of the silicone tube intubation. The results are as follows : 1) Mean diameter of lacrimal opening was 0.93mm and there was no association between epiphora and the size of opening unless the ostium was closed. 2) The granulations were observed in 9 patients out of 16 patients at the time of postoperative 5.8 week, Blinking, twisted silicone tubes, site of the opening, nasal septum, and middle turbinate were considered as the etiologic factors. 3) Because the formation of the granulation was the most common cause of failure, we recommand extubation of silicone tube should be performed at postoperative 1 month.