Abstract: ZrO₂/Cu composite powder was prepared by in-situ chemical route, with which a nano ZrO₂/Cu composite material was prepared by powder metallurgy. TEM observation reveals that there are two crystal types of tetragonal and monoclinic Zirconia particles, and different interracial characterizations exist between the different zirconia particles and copper matrix. With Ansys software, interracial stress was simulated in zirconia with different crystal structures and copper matrix. The results show that the stress is easily concentrated in the tip of monoclinic Zirconia particles and cracks are easily brought than the tetragonal zirconia interface.