A putting instructor includes two rails each having a curved upper surface corresponding to a curved moving pathway of a golf club head while swinging the golf club head relative to the rails, and a link coupled the rails together, to maintain a gap formed between the rails. The curved upper surfaces of the rails are used to guide users to practice putting exercises. Each of the rails includes a graduation disposed on the curved upper surface. Each of the rails includes an outer bulge higher than an inner bar, to form a shoulder between the inner bar and the outer bulge, and having a graduation disposed on a curved upper surface.