Heterostructed Cu2-xS/CuInS2 nanoplates are fabricated by cation exchange reaction. This lateral ring structure has few been reported previously. As-prepared Cu2-xS nanoplates which have roxbyite phase (Cu1.75S) are used as pristine nanoparticles. From lateral part, incorporation of indium is occurred because edge of nanoplates is thermodynamically less stable. Furthermore, we show that heterostructured hexagonal ring could be controlled by tri-n-octylphosphine (TOP) amount. The transformation of each heterostructure depending on shell size was characterized through UV-vis absorption spectroscopy, transmission electron microscopy, and X-ray diffraction measurements.