The purpose of this study was to determine the mechanical factors that govern success in the performance of handspring salto forward stretched with 1/1 turn. The subjects were two all-around gymnasts who registering sophomore in college. By means of three-dimensional film analysis, it was to analyze the sequence of duration phase, angle change of the body joint, and body of the center gravity during performance of handspring. The findings of this study were following as: 1. The sequence of duration phase indicated that Sub.1 has more stride than Sub.2 in the first interval and the shoulder joint has greatly extended, in which the linear movement at take off is transferred into the rotation movement with supporting on the ground. 2. In the several states, sub.1 has more flexor on the elbow of the left on the center of rotation, more twisted on the shoulder joint far from the axis of rotation than sub.2, in which resulted in constant twisting momentum. 3. Body center gravity showed to be low until supporting hands on the ground with taking steps. It was therefore to generate greatly the initial force of handspring based on the rotation of hands. In the fourth, upper extremities is bending forward and lower extremities is extending backward. These results were therefore of interest to determine the magnitude of flight in the air with support of greatly rotation. Of all the variables analyzed, the large stride, high rotation of vertical velocity based on axis of hands, and bending upper extremities forward, are important determinant for successful results.