An automatic rotating decoration includes a rotating body, a support, a driving device connecting the support, and a transmission member connecting the driving device and the rotating body. The support, the driving device and the transmission member all are received in the rotating body. An opening is defined in the rotating body. The support is exposed to the opening. The driving device includes a driving body and an output shaft extending from the driving body. The driving body includes a motor body and a battery seat electrically connecting the motor body. The automatic rotating decoration of the present invention may automatically rotate around the support on another object without additional housing thereby simplifying the structure of the automatic rotating decoration, increasing fun of the automatic rotating decoration and facilitating the handling.