A posture correcting tool is provided which allows a golf player to practice so that the forward inclination angle of the upper-half body when impacting on a ball with a club can be controlled appropriately and extend the ball flight distance. Being a posture correcting tool worn by a player when practicing club swings, it has a wearing unit which can be fixed to the player's waist, a back fitting unit which is rotatably joined with the wearing unit, arranged so that it can fit with the player's back when worn, and can regulate the forward inclination angle of the upper-half body when the player swings a golf club, and an angle indicating unit with which the forward inclination angle can be visually checked.