A Rh(III)-catalyzed C-H cascade annulation reaction of benzamidine hydrochlorides with iodonium ylides has been successfully accomplished, providing an efficient strategy for the synthesis of various 1-aminoisoquinoline derivatives in moderate to good yields. Here, iodonium ylide serves as an accessible and safe carbene precursor. Further derivatizations were implemented to demonstrate the potential utility of this cascade annulation reaction. Furthermore, the photophysical properties of these compounds may have potential applications in photoelectric materials.