To reuse core tubes generally discarded by taking advantage of the characteristics of the used core tubes to be discarded, that is, the characteristics of a cylindrical body equipped with a certain length and the outline, having strength not inferior to wood, lightweight property, water proofing property and machinability.

A structure using paper tubes is constituted in an interior member or an exterior member by arranging the core tubes 1 of desired length at arbitrary intervals or without intervals by making the core tubes of rolled paper after supply of paper to a rotary press as raw material, and by connecting each core tube 1 with a proper connecting means 2.