Abstract: The interaction between underwater pressure wave and bubble is the key to solve the problem of the collapse of bubble cloud. Jet generation is the most significant feature of non-spherical collapse induced by pressure wave. In the present study, we analyze numerically the interfacical evolution of 2D elliptical bubble induced by underwater pressure wave. The results of numerical simulation show that inclinination angle of bubble is dependent on jet direaction, and not on its generation position. Here the inclinination angle is defined as the angle between long axis of elliptical bubble and propagation direction of pressure wave. For inclination angle = 0°, two jets with opposite directions are generated in long axis, and finally the jet pointing towards the propagation of pressure wave plays a dominant role. For inclination angle = 90°, two genenrated jets are symmetrical in the short axis, and the angle between them and the direction of pressure wave is 53.9 °. By analyzing the equation of voricity, it is revealed that the baroclinity is the main mechanism of jet formation, which caused by the mismatch between pressure gradient and density incoherence at the interface. By changing the angle of elliptical bubble, we obtain the phase diagram between inclination angle and jet angle.