The present disclosure provides a lamp holder rotating assembly, comprising a foundation support, an inserted rod, and a rotating head. The foundation support defines a locating slot. The inserted rod comprises a head end and a tail end coupled to the head end. The rotating head defines a groove. The inserted rod is rotatably mounted on the foundation support. The tail end passes through the locating slot. The head end passes through the groove of the rotating head. The head end rotates in the groove along a first direction which causes the tail end rotating in the locating slot along a second direction opposite to the first direction. The present disclosure further provides an illuminating apparatus.