Al2O3 and Cr2O3 coatings were deposited by atmospheric plasma spraying. The tribological properties of coatings against copper alloy were evaluated with a block-on-ring configuration under dry friction conditions at room temperature. Microstructure of powders and coatings were observed using scanning electron microscopy (SEM) and optical microscope (OM). Some thermo-physical properties of coatings were measured. Results showed that the Cr2O3 coating exhibits cracking failure in the sliding condition with a normal load of 500N and a sliding velocity of 0.84 m/s. This failure of the plasma sprayed Cr2O3 coating is explained in terms of its low thermal conductivity.