Objective: To explore the relationship between left behind experiences due to work migration of parents with depressive and anxiety symptoms among left behind middle school stutents, to provide a theoretical basis for the government to formulate intervention policies for mental health of left behind children. Methods: The stratified random cluster sampling method was used to investigate 2 160 children in Poyang and Guangfeng Counties of Shangrao City, Jiangxi Province from April to June, 2019. Finally, 776 left behind children aged 13 to 18 were selected. The Generalized Anxiety Disorder (GAD-7) and Patient Health Questionnaire (PHQ-9) were used to evaluate the depression and anxiety symptoms. Family characteristics and lifestyle behaviors of left behind children were investigated by questionnaire. Results: In terms of gender, the detection rates of both depressive symptoms and anxiety symptoms were higher in girls than in boys. In terms of age, the detection rates of depressive symptoms (43.2%) and anxiety symptoms (39.9%) in left behind children in high school (16-18 years old) were higher than those in middle school (13-15 years old)( 27.3 % and 33.0%). The detection rate of depressive among left behind children significantly differet in sexual, gender ( χ 2= 10.48 , 21.08); the detection rate of anxiety symptoms among left behind children significantly different in sexual, maternal occupation, and paternal educational background ( χ 2=8.66, 5.30, 8.35) ( P <0.05). Conclusion Parent child separation is associated with depressive symptoms in left behind middle school stutents. Mental health of children in middle school stutents is of great significance to the prevention of depression and anxiety symptoms in left behind children.