In this study, transparent Er 2-x Yb x Zr 2 O 7 (x = 0-2.0) ceramics were successfully prepared by vacuum sintering at 1850 °C for 6 h. The phase composition, microstructure evolution and optical transmittance of the transparent ceramics were investigated. The powders and ceramics demonstrate a single-phase defective fluorite structure. All the ceramics exhibit excellent optical performance and the highest transmittance can reach to 76% at 1100 nm when x=1.0. The upconversion and infrared emission under 980 nm exciting were measured and discussed as well. The Er 2-x Yb x Zr 2 O 7 (x=0-2.0) transparent ceramics exhibit efficient upconversion photoluminescence emission in the visible wavelength region at 524  nm, 541  nm, 650  nm and downconversion emission at 1525  nm, 1565 nm, 1646 nm.