A resin-coated steel pipe is provided having excellent mechanical strength and sliding properties. A double coated structure is formed that extends in the pipe's axial direction and has substantially the same cross section. The structure has a thin steel pipe. Attached to the outer surface thereof is a coating layer with adhesive and an alloy resin. That alloy resin is a mixture of a styrenic resin and a crystalline engineering plastic. Further, formed on the outer surface of the alloy resin in a thickness required for mechanical strength and sliding properties is a crystalline engineering plastic. The resin-coated steel pipe exhibits markedly improved adhesion of the crystalline engineering plastic to the thin steel pipe and thus is free from a fear of the exfoliation of the plastic.