As a result of practicing Woodman's method in one case and Downey's method in two cases, done by extralaryngeal approach, and Thornell's method in six cases, done by intralaryngeal approach about the bilateral midline vocal cord paralysis of nine cases, arytenoidectomy in bilateral midline vocal cord paralysis enable to obtain the satisfactory airway. The extralaryngeal approach is facilitated comparatively on operation and is effective in case of laryngeal trauma and obesity, but the damage of tissue is serious. On the other hand, by intralaryngeal approach, damage of tissue is little, recovery after operation is rapid, the contended airway can be obtained and the reoperation is possible, so we regard this method as a more resonable therapeutics.