Abstract: A hinge mechanism suitable for a foldable electronic device has a first body, a second body and a hinging-body. The hinge mechanism includes a first cradle, a second cradle, a pair of pivoting-shafts, a pair of position-limiting elements, a set of gears and a positioning element. The positioning-element is fixed to the hinging-body and structurally independent from the position-limiting elements, pivoted to the pivoting-shafts so as to be detachably assembled with the position-limiting elements. The first body rotates relatively to the hinging-body through the first cradle rotates the pivoting-shaft fixed to the first cradle relatively to the positioning element so as to rotate the set of gears, make the second cradle rotate the pivoting-shaft fixed to the second cradle relatively to the positioning-element and bring the second body for rotation relatively to the hinging-body. Additionally, a foldable electronic device is also provided.