To reduce buzzing noises generated in high-speed rotation by setting two or more spline fitting parts based on a male spline and a female spline in a propeller shaft.

A propeller shaft 6 is constructed by spline fitting a shaft part 16 connected to a yoke 14, a shaft part 20 connected to a yoke 18, and a shaft part 22 arranged between the shaft parts 16, 20 to each other via two positions. On the outside beyond the spline fitting part between a female spline 24 in the shaft part 16 and a male spline 28 in the shaft part 22, a connecting position based on a share pin 32 is arranged, while a connecting position based on a share pin 34 is arranged on the outside beyond the spline fitting part between a female spline 26 of the shaft 20 and a male spline 30 in the shaft part 22. In this way, one of the share pins 32, 34 is broken if an impact is applied, and in the broken part, the shaft can be slid.