Torsion problems for two rods bonded each other by an adhesive layer are investigated. It is assumed in analyses that the mechanical behavior of the adhesive layer is approximated by that of shear springs, and hence the shear stress τ_θz in the adhesive layer can be proportional to the difference of the displacements υ_θ between the upper and the lower surface of the adhesive layer. Making use of the series expansion techniques, we reduce the problems to the infinite systems of linear equations which can be solved numerically. Then, the stress distributions are obtained for various values of mechanical properties of the rods and the adhesive layer. We also investigate the special case of these problems i. e. the torsion of a half space by an adhered rigid rod.