Abstract We investigated the AC transport loss properties on the cylindrically assembled conductors with thin superconductor tapes through the numerical calculations. A rectangular cross-sectional tape with large aspect ratio AR (>1000) of its cross-section and different tape width were used as the strand for constructing the single- or double-layer cylindrical conductor models. Several tape strands were arranged on a cylindrical former, in a parallel way to the conductor axis. Numerical calculation of self-field distributions and AC transport losses were performed, by taking into account the geometry and the arrangements of tape strands under the Bean’s critical state model. The influence of tape width and arrangements of tape strands on magnetic field distributions and transport loss values in the assembled conductors are discussed by using the calculation results of magnetic field distribution inside the conductors.