Since the performance of a circuit breaker which has the spring operating mechanism mainly depends on the dynamic behavior of a coil spring, the analysis of the dynamic behavior of a coil spring is required for a performance evaluation of a circuit breaker. When a spring moves so fast from the releasing state, a lot of energy is used to move a self-weight of a spring. In this study, a release test bed is designed for evaluating the dynamic behaviors of a coil spring. From the release tests, the dynamic behaviors of a coil spring are analyzed. RecurDyn is employed to carry out the computer simulation and results are compared with test results. The actual energy transferred to the follower during high-speed motion is analyzed through the comparisons of the kinetic energy between the experiment and the computer simulation.