Objective To study the relationship between parenting ideas and retarded children's cognition of traffic signs. Methods Traffic sign cognition of 7-  to 15-yearold students with moderate mental retardation was studied by the experimental method. Meanwhile, psychological questionnaires were used to evaluate parents' parenting ideas. Results Traffic sign cognition of retarded children was at a low level, but it grew with age. Mothers' sense of education value was significantly higher than fathers. The parents' life expectation and the sense of education ability in families with three generations were lower than those in families with two generations. The cognition of traffic signs was positively related with parenting ideas. Parenting ideas could significantly predict retarded children's cognition of traffic signs. Conclusion Parenting ideas can affect retarded children's cognition of traffic signs.