Objectives:To explore psychological and behavior patterns of children with malignant tumor at various ages as well as their influencing factors in order to provide references for clinic treatment. Methods:Totally 120 children with malignant tumor were in-vestigated with Rutter behavior questionnaire. Together with clinic examination and intensive talks,the major influencing factors were clarified. Results:Among the 120 children,detection rate of behavior problem was significantly higher in 54.6% aged under three,61.5% aged between four to seven,24.3 aged between eight to fourteen than in control group(10.7%),with statistical significances(P<0.01). Conclusions:Major influencing factors for behavior problems of children with malignant tumor include education methods of parents,family intimacy,responses of both children and parents to tumors,selection of care-taker. Besides,individual psychological and physical treatment should be provided to enhance their responding ability and cultivate their characteristics,ultimately promote their sound development.