A reinforcing arrangement for reinforcing a joint portion between two support units of a foldable furniture object, comprising a first mounting unit which comprises a first mounting body and a first guiding member outwardly protruded from the first mounting body mounting on the first support unit; a second mounting unit which comprises a second mounting body and a second guiding member or a second guiding groove complimentary to and moveably engaging with the first mounting unit to define a maximum extending angle of movement, thereby the first and second support unit are guided to lock into position at an unfolded position at the maximum extending angle and to unlock at a folded position; and a connecting unit pivotally connecting the first support unit and the second support unit between which the two mounting units are positioned, thereby the joint portion is reinforced.