A large number of child seating and restraint systems are currently available on the market. This paper presents experimental data from impact sled tests in order to discuss the relative merits of several design concepts. Both seats and harnesses were considered in the study. They were attached to the vehicle by a variety of techniques including: a hookover seat, a hookunder seat, an adult lap belt, an auxiliary strap around the adult seat back, and combinations of these techniques.Tests were conducted with seats facing forward, sideways, 45 deg oblique, and rearward. Test subjects were commercially manufactured three-year anthropometric test devices and test dolls fabricated at The University of Michigan representing a 3-month-old infant. Head and chest accelerometers were mounted in the dummies. High-speed photographic coverage from the front and from the side was used to record the kinematics of the event. Conclusions are drawn concerning attachment of the various seats to the vehicular seat structure, dynamic interaction between the vehicle seat and the child seat or harness, structural integrity of various devices, and protection offered by the various design concepts in front, side, and rear-end collisions. Credit should be given to the National Highway Safety Bureau,* U.S. Department of Transportation, for funding this study under Contract FH-11-6962.