Abstract: This water-proof lamp socket structure includes a lamp socket, a ring body, an upper cover, and a water-proof ring. The lamp socket is constituted by two semi-cylinders in relative position, with a fluted penetration hole formed at both sides of its bottom. An interior wall of the lamp socket has inner threads and its exterior has a ring body. A curved groove is formed at an upper portion to accommodate a wire. The bottom upper cover inside the groove has a sharp nickel plate which a bottom upper cover with the same curved groove is placed on top of in order to penetrate the wire by the nickel plate for conduction. The bottom of lamp socket is encased with a slight trapezoidal water-proof ring. The water-proof ring is clicked into holes at both sides of the lamp socket by two catch blocks at its top in order to fix it inside the lamp socket so that it will not easily fall off.