Hammer throw is one of the competitive events with high techniques in track and field. Theoretically, the most important factors contributing to distance are initial speed, hight and angle at release. The purpose of this study was to investigate the fluctuation of three dominant parameters of hammer throw motion. A elite hammer thrower, who is the present Taiwan record holder, was filmed simultaneously with two high speed (120 Hz) cameras during the university athletic meet. The 3D kinematic data were transformed, and the selected parameters were calculated by Peak Motus motion analysis software. The results indicated that hammer speed and vertical displacement increases gradually during a throw, but this increasing trend has one fluctuation superimposed in each turn. The increase in hammer speed within each cyclic fluctuation coincides approximately with the doublesupport phase of throw. The three initial parameters speed, hight and angle were 25.34 m/s, 1.82 m and 39.17 deg respectively.