To improve the low resistance of ceramics to tensile stress, many techniques, for introducing and retaining surface compressive stress have been suggested. In present work, in order to introduce the compressive stress on the surface of TZP ceramics TZP-Al2O3 composites were made with infiltration technique. Highly porous 3Y-TZP pre-sintered specimens were submerged in AlOOH(boehmite) sol and the sol penetrated into them through open pore channels with moderate depth after that specimens were sintered. It was known that controlling the number of infiltration time can vary the amount of Al2O3 phase and the fraction of alumina at surface reached up to 18%. The depth of composite surface layer were 100~200 ${mu}{ extrm}{m}$, and these were acceptable in surface strengthening which were proved by Vickers hardness indentation method.