Abstract: A reciprocal sliding friction and wear tester simulating the motion of piston-cylinder liner pair was performed to comparatively investigate the wear-resistance of microarc oxidation coating on aluminum alloy, Cr-plating coating, and wear-resisting P-V-Cu cast iron, by sliding against carburized and nitrided AISI-1045 steel under the lubrication of a two-stroke motorcycle machine oil. The morphologies of the original and worn surfaces of the microarc oxidation coating were observed on a scanning electron microscope. The morphologies of the worn surfaces of the Cr-plating coating and wear-resisting P-V-Cu cast iron were also observed on the same scanning electron microscope, and the wear mechanism and its affecting factors were accordingly discussed. As the results, the microarc oxidation coating showed much better wear-resistance than the Cr-plating coating and the P-V-Cu cast iron. This was attributed to the specials microstructures of the microarc oxidation coating. Namely, the micro-cavities in the microarc oxidation coating were able to entrap the lubricating oil and hence to reduce the friction and wear. Such a kind of the oil-entrapping capacity of the micro-cavities was remained after the friction and wear test, because the morphologies and structures of the micro-cavities remained almost unchanged thereafter. Moreover, though the microarc oxidation coatings of different thickness had different running-in period and running-in wear mass loss as well, they recorded a slight variation in the wear mass loss during the steady-state sliding process.