For a long time, tracheal cannulas of various forms and materials were developed to prevent the occurrence of tracheal stenosis in patients who need longterm tracheal cannulation. Recently, Silicone-Rubber has been developed as a raw material for ordinary tracheal cannula and T-tube. Despite continuous development of the new models and materials, still there remain many serious problems of treatment and prevention of tracheal stenosis, which follows the formation of granulation tissue due to chronic irritation and underlying inflammation of respiratory mucosa. Nowadays, 'Silicone Tracheal Opening Retainer' which has been designed to maintain the respiration, to preserve the phonation ability, and to reduce the irritative effect on the respiratory mucosa was developed. The authors performed the insertion of the 'Silicone Tracheal Opening Retainer's in 8 patients who need longterm tracheal cannulation in Severance Hospital from Feb. 1983 to Sep. 1984. The authors experienced several advantages such as decreased formation of granulation tissue on the respiratory mucosa, easy insertion and removal, easy cleansing, decreased tracheo-broncheal secretion, decreased discomfortness on neck motion and ability in phonation with speech valve.