We apply the random matrix theory to small metallic grains in different spin states of S = 0, 1/2, 1, 3/2, 2, 5/2, .., and find that there exist theoretical critical level spacings de at which the superconductivity would breakdown. We also find that the higher the spin state, the smaller the critical level spacing, and for the state of S = 0superconducting enhancement actually exists.