A connector structure having a first connector including a first housing and a plurality of first terminals provided in the first housing, and a plurality of second connectors each including a second housing and a second terminal provided in the second housing, the second connectors being configured to be inserted into and pulled out from the first connector in a longitudinal direction in a mutually aligned and adjoining relationship in a lateral direction, the connector structure comprising: a moveable member provided on at least one of side surfaces of each second housing facing in a vertical direction which is orthogonal to the lateral direction and the longitudinal direction so as to be resiliently moveable in the vertical direction; a locking engaging portion provided on the moveable member; and a locking engaged portion provided on the first housing so as to be engaged by the locking engaging portion when the second housing is received in the first housing; characterized in that the connector structure further comprises: a longitudinal movement restricting protrusion provided on one of side surfaces of the moveable member facing in the lateral direction so as to move in the vertical direction in synchronism with the locking engaging portion; and a stopper portion (56, 58) provided on another of the side surfaces of the moveable member facing in the lateral direction so as to move in the vertical direction in synchronism with the locking engaging portion, and configured to restrict a movement of the longitudinal movement restricting protrusion of the laterally adjoining second housing in the longitudinal direction when the said second housing positionally coincide with the laterally adjoining second housing with respect to the longitudinal direction; wherein the longitudinal movement restricting protrusion and the stopper portion (56, 58) are configured to be placed out of alignment with each other with respect to the vertical direction to allow the longitudinal movement restricting protrusion to move in the longitudinal direction relative to the stopper portion (56, 58) of the laterally adjoining second housing when the moveable member is moved in the vertical direction so as to disengage the locking engaging portion from the locking engaged portion. a moveable member provided on at least one of side surfaces of each second housing facing in a vertical direction which is orthogonal to the lateral direction and the longitudinal direction so as to be resiliently moveable in the vertical direction; a locking engaging portion provided on the moveable member; and a locking engaged portion provided on the first housing so as to be engaged by the locking engaging portion when the second housing is received in the first housing; characterized in that the connector structure further comprises: a longitudinal movement restricting protrusion provided on one of side surfaces of the moveable member facing in the lateral direction so as to move in the vertical direction in synchronism with the locking engaging portion; and a stopper portion (56, 58) provided on another of the side surfaces of the moveable member facing in the lateral direction so as to move in the vertical direction in synchronism with the locking engaging portion, and configured to restrict a movement of the longitudinal movement restricting protrusion of the laterally adjoining second housing in the longitudinal direction when the said second housing positionally coincide with the laterally adjoining second housing with respect to the longitudinal direction; wherein the longitudinal movement restricting protrusion and the stopper portion (56, 58) are configured to be placed out of alignment with each other with respect to the vertical direction to allow the longitudinal movement restricting protrusion to move in the longitudinal direction relative to the stopper portion (56, 58) of the laterally adjoining second housing when the moveable member is moved in the vertical direction so as to disengage the locking engaging portion from the locking engaged portion. a longitudinal movement restricting protrusion provided on one of side surfaces of the moveable member facing in the lateral direction so as to move in the vertical direction in synchronism with the locking engaging portion; and a stopper portion (56, 58) provided on another of the side surfaces of the moveable member facing in the lateral direction so as to move in the vertical direction in synchronism with the locking engaging portion, and configured to restrict a movement of the longitudinal movement restricting protrusion of the laterally adjoining second housing in the longitudinal direction when the said second housing positionally coincide with the laterally adjoining second housing with respect to the longitudinal direction; wherein the longitudinal movement restricting protrusion and the stopper portion (56, 58) are configured to be placed out of alignment with each other with respect to the vertical direction to allow the longitudinal movement restricting protrusion to move in the longitudinal direction relative to the stopper portion (56, 58) of the laterally adjoining second housing when the moveable member is moved in the vertical direction so as to disengage the locking engaging portion from the locking engaged portion.