Abstract: The headrest (2) is liftable, comprises wings (11) and (12) and is provided with passages (3) for the belting (C) of the motorcar's safety belt. The backrest (1) does also characteristically comprise passages (4) for the belting (C) of the motorcar's safety belt, these latter passages because of the fact of being positioned in a lower position as compared with those of the headrest (2) being provided to be used when the child is of a short size so that it can thus be properly held back by the safety belt. A characteristic feature also lies in the fact that the wings (11) and (12) are fitted in a linked connection to the sides of the headrest (2), this latter having a mechanism (13, 14, 15 and 18) linking them to each other and locking them thus selectively setting them at a given angle with respect to the headrest (2).