The invention aims at producing a belt guiding element for a child safety system, in particular for a child seat, providing a high safety level and particularly highly comfortable use when the safety belt is inserted into said element and when the belt is removed therefrom, for example when the safety belt is used on the child to be protected. Therefor, the inventive belt guiding element comprises a slot (130) for receiving a safety belt (40), on the vehicle side, in particular a three-point belt, and a locking element (100) capable of being open or closed. Said locking element (100) enables, in open position, the safety belt (40) to be inserted into the slot (130) or the safety belt previously inserted into the slot (130) to be removed, and, in closed position, the insertion or removal of the safety belt (40) to be prevented. Said locking element (100) consists of a lock lever which can pivot about a pin (110) spaced apart from the slot (130)