The Kinematic Comparison of Tsukahara 900° on Men’s Vault Graduate Student:Yung-Hsi Lin 2004/07 Advisor:Chien-Lu Tsai ABSTRACT The purpose of this research was to compare the different kinematic variables between the two Gymnastics (subject A and subject B) when they were performing the movement of Tsukahara 900°. Two Redlake high speed digital cameras (125Hz,Shutter 1/625s) were used to record the element of Tsukahara 900°. The results were shown as follow. The peak approaching velocity of subject A was 9.67m/s, the horizontal velocity of touch down on the board was 7.88m/s, the horizontal velocity of takeoff board was 5.79m/s, leaving vault vertical velocity was 3.54m/s and the leaving vault angle was 67°. The peak height of center of mass (COM) in the second flight period in the air was 2.92m, In the twist period, the averaged angular velocity was 19.74rad/s, the greatest twisting velocity was 27.49rad/s, the landing angle of COM was 75°. The kinematic data of subject B were, the peak of approaching velocity 9.19m/s, the horizontal velocity of touch down the board was 7.36m/s, the horizontal velocity of takeoff board was 5.66m/s, leaving vault vertical velocity was 3.50m/s and the leaving vault angle was 59°. The height of COM in the second flight period in the air was 2.89m, in the twist period, the averaged twist angular velocity was 16.74rad/s, the greatest twisting velocity was 23.25rad/s, the landing angle of COM was 42°. Subject A shows better approaching momentum, horizontal and vertical twisting velocity than subject B. The results showed that subject A preformed better approaching velocity, takeoff technique, twist movement and landing technique than subject B. we suggested subject B had to improve the technique of approaching velocity, the ability of take off, twist angular velocity and landing stability. Key words: vault、kinematics、Tsukahara 900°