adjustment stem 314 and includes a teeth shaped female engaging portion 321 inside a first fastening hole 322 and a plurality of second fastening holes 323 on an outer side the first fastening hole 322 corresponds to the annular groove 316 of the adjustment stem 314 when the adjustment stem 314 is inserted into the adjustment holder 32 the male engaging portion 315 and the female engaging portion 321 are engaged the anchor element 317 runs through the first fastening hole 322 to butt the annular groove 316 to form a firm coupling of the adjustment member 31 and adjustment holder 32 the second fastening holes 323 are used to fasten the assembly dock referring to fig1 after the adjustment assembly 3 and led lamp set 2 are assembled if adjusting light illumination angle is desired unfasten the anchor element 317 to disengage the male engaging portion 315 and the female engaging portion 321 turn and adjust the engaging angle between them until reaching a desired angle and engage the male engaging portion 315 and the female engaging portion 321 again and fasten them together through the anchor element 317 then light illumination can be achieved as desired refer to fig1 through 20 for the led lamp 1 of the invention that further includes an assembly dock 6 which can be coupled with a plurality of led lamp sets 2 and adjustment assemblies 3 according to requirements and can be fabricated through a molding process in this embodiment three sets of the led lamp sets 2 and adjustment assemblies 3 are provided the assembly dock 6 has a cavity 61 at a rear end formed at an inclined angle according to requirements the adjustment holders 32 of the adjustment assembly.