Abstract: Dynamics of bubble oscillation formed during underwater explosions were studied in a water tank. The expansion and collapse of the bubble pictures created by the explosion of the short length-diameter ratio(1.05) PETN were captured by a high-speed camera. The geometry of the bubble is approximately spherical. The radius and period of oscillation of the bubble increment with the charge weight. The position of the bubble is almost constant during its expansion, but when the bubble is growing smaller, the bubble rises more distinctly. The contract velocity in the bottom of bubble is faster than that of the up surface caused by the influence of gravity; a water jet was formed at the last stages of the bubble collapse.