Swing tempo, rhythm and swing plane are shown to be important in maintaining the performance. However, nearly all studies utilized optical motion capture system for the planar behavior of golf swings and the movement of the club. The primary aim of this study was to develop inertial measurement unit sensor-based swing motion analysis algorithm, and validate against an optical motion camera system by comparing the estimated clubhead trajectories during the golf swing. Then, the tempo, rhythm and functional swing plane were investigated using a validated wearable inertial sensor. Fourteen male golfers performed repeated swings for three clubs (driver, 7-iron, and wedge) and at three distances (30 m, 50 m, and 70 m using the wedge). The swing tempo of all the participants was consistent across different clubs. The swing rhythm tends to decrease for club types with less carrying distance. The functional swing plane slope tends to decrease for club types with greater carrying distance. Our study demonstrated a potential application of a wearable inertial measurement unit system for analyzing golf performance parameters.