The present invention relates to a mouth-tube assembled to a tip of a saxophone wind tube, an operating rod is installed on an upper portion of the mouth-tube. The feature of the invention is that: a cover tube, having a spiral spring inserted therein, protruding downwards is installed on a lower end of the operating rod, furthermore, the spiral spring protrudes from the cover tube and is leaned on the mouth-tube. According to the aforesaid structure, the conventional spring plate is replaced with a spiral spring to reduce hole drilling and screwing process, whereby structure and production process is simplified, achieving a decrease in capital.