A conceptual design of a heliotron power reactor, which is a steady state reactor with a continuous helical coil, has been developed. The major features of the heliotron reactor include modular blanket and shield structure, modified winding helical coil, local divertor for impurity and ash removal, and NbTi conductor with subcooled He-II bath cooling. The objective of this design study is to present a viable design of the heliotron power reactor.