<p>&nbsp;&nbsp;&nbsp;&nbsp;This study aimed to present the practical knowledge and investigate effective techniques to improve performance in the high jump. The subject was a male Japanese top class high jumper whose personal record was 2 m31. Progress in high jump performance was shown by an increase from 2 m22 in 2012 to 2 m31 in 2014, and kinematics data were collected at competitions to assess the factors involved in achieving best record. The results were as follows. <BR>1. The subject focused on high jump technique training during periods between competitions, and on improvement in strength training at without competition periods. Considering effects of training, this training protocol was logical. <BR>2. The subject changed from single-arm action at takeoff to double-arm action and improved its techniques during this study. This change improved high jump performance by increasing force on takeoff. <BR>3. The results of this study suggested different from general theory which is provided by previous study. It means that there is possibility to discover new theory by investigating individual case. <BR>&nbsp;&nbsp;&nbsp;&nbsp;These results suggest the hints to improve high jump performance and indicating the importance of individual longitudinal investigation.</p>