A connecting structure for coupling connectors includes a male connector, and a female connector connected to the male connector. The male connector includes: a base; a first terminal portion provided on an upper surface of the base; and an edge portion protruding from the upper surface of the base to surround the first terminal portion. In particular, the edge portion includes a coupling protrusion protruding from an outer surface of the edge portion. In addition, the female connector includes: a second terminal portion to be connected to the first terminal portion; an inner seal that is provided in the second terminal portion and inserted inside the edge portion; and a casing including an inner space where the second terminal portion is provided, and a coupling groove having a shape corresponding to the coupling protrusion.