Abstract: A decorative lamp bulb and socket adapter is provided without a conventional fixed sleeve. The assembly takes advantage of contact surfaces of the sealing lug at the bottom of the bulb, a top surface of the sealing socket and the bottom surface of the bottom edge of the bulb. The lapped surfaces in both horizontal and vertical directions form a solid sealing structure to prevent water from permeating into the inside of the socket adapter. By clamping the terminal portion of the bulb with the clamping portion of the conducting strips, the connection between the electrodes at the terminal portion of the bulb and the clamping portions of the conducting strips is maintained.