The authors previously developed a method for measuring the safety behavior of children in a dashing out situation by using a simulated catalog situation. 164 preschool children participated in the present study. Two experiments were conducted to investigate the factors which may affect the safety behavior of children. The first experiment examined whether the difference in traffic condition can influence safety behavior. Results showed that children were more likely to respond safely in a dashing out situation if audiovisual information existed when they were playing. It seemed very important to increase the sensitivity of children to moving vehicles. In the second experiment, the effect of verbal instruction on safety behavior was examined. Different types of instruction were given to three groups of children immediately before they began to play in the experimental situation. The rate of children showing safe behavior increased gradually in proportion as the content of instruction became clearer and more detailed. However, differences in the rate were not large, and even in the detailed instruction group nearly 40% of the children showed unsafe behavior. These data seem to indicate the inferiority of verbal instructions with regard to behavior change.