A turning mechanism is adapted to a projector including a base and a zoom lens set in a base for turning a zoom bar of the zoom lens. The turning mechanism includes a fixed element and a movable element. The fixed element is suitable to be fastened to the base and has a pair of slide tracks. The movable element has a pair of slide edges, a pair of slide hooks, and a turn portion. The slide hooks lock the slide tracks respectively, and the slide edges are supported by the slide tracks respectively. Therefore, the movable element substantially slides around a light axis of the zoom lens relative to the fixed element, so as to move the turn portion to turn the zoom bar.