The purpose of this study is to investigate the relationships between handle movement and leading distance of handle affecting increase and decrease of hammer head speed during turn phases. Forty-four male throwers (throwing record: 80.50－44.17m) participated in the study. Throwing motions were videotaped on high-speed VTR cameras, and three-dimensional coordinates were calculated using a DLT method. Kinematic parameter were calculated such as the hammer head speed, the leading distance of handle, the handle velocity in the rotating plane coordinate system where X_icr is the hammer head speed direction and Y_icr is the direction connecting the hammer head and the instantaneous rotation center. Fundamental factor were summarized as follows: (1) The increase and decrease of leading distance of handle was consistent with the increase and decrease of handle velocity in the Y_icr direction. That is, when the thrower pulls the handle toward the center of instantaneous rotation, leading distance that affects the hammer head speed increases as a result. (2) It became clear that the acceleration strategy for increasing the hammer head speed in the first half and the second half of the double support phases is different from the acquisition pattern of the leading distance of handle.