Disclosed is an optical disc having angular information and a wobble track. A wobble signal generated according to the wobble track includes a phase corresponding to an angle of the optical disc. A detecting system for detecting the angular information of the optical disc is also disclosed, which includes a wobble signal detecting apparatus, a reference clock signal generating apparatus, and a phase comparator. The wobble signal detecting apparatus is used for detecting the wobble track on the optical disc to generate a wobble signal. The reference clock signal generating apparatus is used for generating a reference clock signal according to the wobble signal. The phase comparator is used for comparing the wobble signal and the reference clock signal to obtain the angular information of the optical disc. Alternatively, the wobble signal detecting apparatus can be used for detecting the wobble signal on the optical disc.