The plasma resistance of translucent Y2O3 ceramic prepared by slip casting was studied and compared with that of translucent Al2O3 ceramic. The color after etching is almost unchanged for transparent Y2O3, while the color turns grey after etching for translucent Al2O3. The in-line transmittance (IT) for transparent Y2O3 is almost unchanged before and after etching while IT reduces similar to 5% after etching for translucent Al2O3. The etching depth of translucent Al2O3 ceramic (similar to 270 nm) is deeper than that of transparent Y2O3 ceramic (similar to 200 nm). The surface morphology of transparent ceramics Y2O3 and Al2O3 using optical microscope and SEM both show that the etching traces of translucent Al2O3 ceramic are more obvious than that of Y2O3.