Demura, S and Miyaguchi, K. Evaluation of muscle power exerted by explosive gripping. J Strength Cond Res 23(2): 465-471, 2009-To establish the evaluation method for muscle power exerted by explosive gripping, this study aimed to examine the reliability of parameters and the muscle power output properties in both genders. Fifteen young men and 15 women participated in this study. Each subject carried out explosive grip tests twice using a simple muscle power measurement device (weight loading method), each time with 20, 30, 40, and 50% loads of maximum grip strength (MGS) by isometric contraction. Peak power was drawn from the product of the measured peak velocity and relative loads. The reliability of each parameter in all loads was good (interclass correlation coefficient >0.75) for both genders. The MGS showed insignificant correlation with all parameters. Peak power values were larger in men than in women for all loads, and the women's values were 44.5-52.2% of the men's. A large gender difference was found for 20% MGS. In conclusion, the reliability of muscle power parameters measured by the measurement device in this study is high. It was judged that the device used in this study can properly evaluate the gender difference in muscle power output properties by explosive gripping.