The design of sports equipment is one of the major factors affecting the sport performance. Baseball is a typical sport which sports equipment plays an important role. The material, shape, size, inertia and vibration characteristics of bat will affect the striking performance. The purposes of a good baseball bat are enhance performance and reduce injury. These purposes can be achieved by designing the baseball bat according proper biomechanical characteriztics. Besides, the players should realize the striking techniques and the bat characteristics to perform an optimum strike. The objective of this study was to thoroughly understand the biomechanical characteristics of baseball bat. The wood bat used in professional baseball league were tested by accelerometers, and Finite Element Method was used to simulate the modal analysis. The results shows that power point, center of percussion and vibration node have different locations, which indicated that the most comfortable striking point is not necessary to be the most powerful point. But these three major points located closely which are the location so called sweet spot.