In order to find zirconia materials that have better balance in various properties, we have studied zirconia with different levels of translucency. It is clear that the most robust and efficient method of enhancing zirconia’s translucency is to increase the yttria content. Therefore, in this presentation, the behaviors of 3Y-, 4Y- and 5Y- stabilized zirconia was evaluated, with the comparison to lithium disilicate glass-ceramic for which excellent aesthetic and good clinic results have been documented. In particular, the crack resistance under static and cyclic conditions was in details studied by double torsion methods. 3Y- and 4Y- stabilized zirconia can benefit from the transformation toughening effect and transformed grains were clearly observed in the vicinity of crack path, resulting in toughness of 5.0 MPa· and 4.0 MPa·, respectively. Furthermore, due to the fine microstructure (almost no bridging), the loss of crack resistance (fracture toughness and threshold) under cyclic conditions were small (about 6%). 5 mol% yttria stabilized zirconia could not benefit from the extrinsic toughening effect, thus had rather similar fracture toughness (about 3.0 MPa·) as lithium disilicate glass-ceramic. Nevertheless, due to the stronger crack-tip Zr-O-Zr bonds, it still has higher resistance to subcritical crack growth and also higher (50%) threshold to crack initiation.