Plug connector, receptacle connector and connector assembly

A connector assembly includes a printed circuit board (PCB), a plug connector and a receptacle connector. The receptacle connector includes a shell and a light guiding structure and is disposed on the PCB. The light guiding structure is disposed on the shell and includes a light input surface and a light output surface. The light input surface aligns with a light source of the PCB. The plug connector includes an insulating body and a light guiding drawbar including a light input surface and a drawbar portion. The light input surface of the plug connector is disposed on the surface of the insulating body and the drawbar portion bulges out of the insulating body. When the plug connector is connected with the receptacle connector, the light output surface of the receptacle connector aligns with the light input surface of the plug connector.