inner space thereof and then the lamps lamp bases or sockets are fitted securely into the inside of the clamping socket thus various decorative lamp string assemblies can be formed application_number US 38902195 A description the support assembly according to the first embodiment of the present invention is shown in fig2 in which a lamp string 1 in series connection of lamps 1a 1b 1c and 1d a strut support 2 and a plurality of clamping sockets 3 are included generally the support 2 is made of plastic material and has rigidity along the two longitudinal side edges of support 2 recess 200a and 200b are formed at the set position and pillars 201 each vertically projected from bottom face of support 2 between recess 200a and 200b are formed clamping socket 3 is in the form of a u shape body with open end the section of inner space formed and surrounded by upper bottom and two side walls is the same as the sectional shape of support 2 two tips of the side walls bend inward and a hole 301 is formed at the bottom to be fitted securely with pillar 201 of the support 2 in the present invention when the recesses of support 2 are engaged with the open end of each clamping socket the two side edges of support 2 can be clamped securely by the two side walls of clamping socket 3 at.