A coaxial connector includes a body, a female connector, and a detecting structure. The female connector has a pillar, and the pillar connects with the body. The detecting structure has a movable socket and a flexible conductor, wherein the movable socket is slidably sheathed on the pillar, and an interval space is formed between the movable socket and the pillar. The flexible conductor is located in the interval space, and has a detecting terminal. A part of the detecting terminal exposes to outside the movable socket, the movable socket pushes the flexible conductor toward the body in order to electrically connect the detecting terminal with the body. Hence, an RF (radio frequency) signal switching element on a mother board can be driven to switch between a build-in RF unit and an external RF unit.