Safety of children as car occupants raises a specific problem: it is necessary to take into account two factors which are particular to them: their very fast growth and their behavior, which corresponds to a need for movement.An analysis of statistical and accidentological data, points to the fact that whereas traffic accidents account for 25 % of adult deaths, they account for nearly 50 % of deaths for children (all kinds of road-users).Measures were adopted in France; such as the obligation for children of less than 10-years-old to travel on rear seats of cars and the definition of an homologation procedure for children restraint devices, with the aim of limiting the consequences of these accidents.The most common restraint devices look like little individual seats and are designed to protect young children (less than 3-years-old). Recently, new restraint devices, called “cushions”, were developed. They are designed for children of over 3 and they can be used almost up to small adult sizes. They enable some improvements in the location of the adult belt on the child's body; thus, improving safety.Several cushions were submitted to simulated frontal collisions, by using them in a car body fixed to a sled; the impact severity was similar to that encountered in some European restraint system, certification tests. These runs brought to light the dynamic response obtained with these cushions and their efficiency, as regards the restraint of child dummies.From these results and with the help of an anthropometric survey concerning the heights of children between 3 and 10 years old, cushion shapes were defined, to be used simultaneously with a 3-pt -belt. This cushion was tested with the 3-year and 6-year child dummies, and proved to be very efficient as regards safety; it also appears suitable from the standpoint of comfort.