A rotation mechanism for an umbrella comprises a vertical columnar (1), a rotating shaft (2), a ratchet (3) having a plurality of ratchet teeth (30), a magnet block (4) a pressing assembly (5), a limiting room (10); wherein the magnet block (4) is movably located inside the limiting room (10); when the ratchet (3) rotates in a first direction, the magnet block (4) departs from the ratchet teeth (30); when the ratchet (3) rotates in a second direction, the magnet block (4) is attached and magnetically attracted to the ratchet teeth (30); the pressing assembly (5) is connected to the rotating shaft (2) and presses against the two side surfaces of the ratchet (3). The present application also discloses an umbrella comprises the rotation mechanism. The structure is simple and it is easy to assemble.