An apparatus prevents developer wraparound in a wet electrophotographic printer using wraparound preventing units. Each of the wraparound preventing units has varied diameter parts formed at both ends of a developing roller, and matching parts formed at both ends of a metering roller to correspond to the varied diameter parts of the developing roller. Since the varied diameter parts and the matching parts are respectively installed at both ends of the developing roller and the metering roller, developer wraparound is not generated in the developing roller and a photosensitive roller during development.