The purpose of this study is to investigate the correlation between parent\'s anger expression modes and their children\'s anger expression modes, and to find out the difference between the anger expression modes and assertive behavior of children. The subject of this study was 500 Children in the 4th, 5th and 6th grades of three elementary school and their parent in the Seoul Metropolitan area. To analyze the data, frequency and percentage were obtained by SAS statistical program. And Cronbach\'s α were computed to check the reliability of the measuring instrument. And χ²-test, t-test and F-test to get the conclusion from this research. The results of this study are followed. First, there was no significant difference between the children\'s anger expression mode and their gender. But there was a significant difference in the assertive behavior and their gender. Second, there was no significant difference between the parent\'s anger expression modes and their son. Third, there was no significant difference between the parent\'s anger expression modes and their daughter. Fourth, according to boy\'s anger expression modes, anger-out group obtain higher scores aggression and assertion in assertive behavior. And according to girl\'s anger expression modes, anger-out group obtain higher scores of aggression and anger-in group obtain higher scores of passivity and assertion in assertive behavior. In conclusion, mother\'s anger expression modes and daughter\'s anger expression modes have closing relationship. And boy\'s anger-out group obtain higher scores aggression and assertion in assertive behavior. And girl\'s anger-out group obtain higher scores aggression and anger-in group obtain higher scores passivity and assertion in assertive behavior.