To compare mental health,rewards and punishment,etc.among left-behind children and non-left-behind children in rural area,overall 2307 left-behind children in rural area were selected randomly from 6 primary schools and investigated with questionnaire using cluster stratified sampling.Between left-behind children and non-left-behind children,significant differences were observed in interpersonal anxiety,loneliness tendency,body symptom,phobic symptom and total score of anxiety tendency.Left-behind children obtain little prize and more punishment.Left-behind children frequently play with left-behind children.Significant differences were observed in hiring out to make money between left-behind children and non-left-behind children.