Abstract: The problem for spherical cavitation bifurcations in superealstic materials is formulated in the first section of the paper. Then, two new exact solutions of the spherical cavitation bifurcation for the modified Blatz Ko material are obtained. The stress concentration factor and discontinuity at the vavitation are given when the cavity appears. Finally, the cavitation bifurcation solutions are numerically computed. One can see that the stress concentration near the cavitation is an important cause of the g...