Porous Yttria Stabilized Zirconia (YSZ) with macropore and nanopore was fabricated from sintering and leaching the mixture of YSZ and different types of ZnO. When we used nano-sized crystalline particle, porous YSZ with submicron pores was obtained. In the case of the spherical 30 nm to 100 nm ZnO particles obtained from hydrolysis of zinc acetate in methanol, 2 approximately 10 nm sized pores was observed in the YSZ. From the results, it was suggested that crystalline ZnO particles grew up while the spherical noncrystalline ZnO particles were enclosed in YSZ matrix in the sintering process.