To provide a composite tubular body which is best suited for an interlocking belt and highly heat-conductive and further, capable of deterring a progress in the wear of a fluororesin layer even after running tens of thousands of paper while showing outstanding mold release property.

This composite tubular body 4 is structured of a base layer tubular body 9 of a polyimide resin containing a heat-conductive inorganic powder and a two-tier fluororesin coating layer including at least a first outer layer 11 and a second outer layer 12 formed on the outer surface of the base layer tubular body 9. The first outer layer 11 of the base layer tubular body 9 side contains the heat-conductive inorganic powder. In addition, the base layer tubular body 9 and the first outer layer 11 are preferably laminated on each other through a primer layer 10.