Nanoindentation tests were conducted on zirconia ceramics to measure the mechanical properties, in which hardness and elastic modulus of zirconia ceramics can be obtained by the continuous stiffness measurement. Different penetration depths and strain rates were employed to examine the fluctuation of hardness, modulus and deformation. The test results indicate that modulus increases slightly with increasing displacement, but hardness and the percentage of elastic recovery basically remain unchanged. For the same penetration depth, hardness, modulus and the percentage of elastic deformation are all larger under higher strain rate.