A guide mechanism and the optical drive utilizing the same. The guide mechanism includes a guiding base, a first axial fixing member, a driver, and a rotary structure. The guiding base comprises a first opening and a second opening. The first axial fixing member is disposed at a side of the guiding base. The driver, disposed at an opposite side of the guiding base, comprises an opening and a second axial fixing member. The rotary structure is fixed between the first axial fixing member and the second axial fixing member, comprising a spindle and a magnetic structure. The spindle comprises an operating region and a connecting portion having a maximum outer diameter smaller than a minimum outer diameter of the operating region. The magnetic structure is attached to the connecting portion and disposed in the opening.