A locking mechanism for a foldable motorized vehicle for locking a main frame body thereof comprises a pulling arm, locking shafts, shaft sleeves, elastic elements, and locking pins. The shaft sleeves are fixedly positioned in parallel below the main frame body and respectively sleeved on the locking shafts. Each of the locking pins is fixed on one end of a corresponding locking shaft and penetrates corresponding locking holes on the main frame body. Each elastic elements is sleeved on the corresponding locking shaft and pressing against the locking shaft and the corresponding shaft sleeve, respectively. The pulling arm comprises a pulling rod pivoted on one end of one locking shaft, and a connecting member with one end pivoted on one end of the other locking shaft, and the other end pivoted on the pulling rod.