A lamp socket has a socket body with a plugging section in which a lamp plug is removably plugged. In the plugging section, there are a central terminal and a side terminal. An insulation seal member provides electrical isolation between the central terminal and the side terminal and is prevented from dislodging when the lamp plug is removed from the socket body by forming a structure from at least one of the central terminal and the insulation seal member which are adapted to fit into one another. Thus, the removal of the insulation seal member when the lamp plug is plugged out of the socket body can be prevented by the central terminal of the socket body and/or the insulation seal member itself. Therefore, there is no need to install an additional component such as a stopper. Thus, the number of components and its manufacturing cost can be reduced compared with a conventional lamp socket. In addition, this avoids problems such as defects in the lamp or the lighting mechanism caused when a lamp is detached from the lamp socket and replaced with new one, and the insulation seal member thereof is missing, displaced, jammed, cracked or the like when a lamp plug with a replacement lamp is re-plugged in the lamp socket.