Abstract: Objective To examine the impacts of parental working out-of-home on behavior and mental status among left-behind children. Methods A questionnaire survey about adolescent health risk behavior and psychological status was conducted among 2 139 pupils(810 left-lehind children under age of 14 years)from 2 full-time schools.Results For the 810 left-behind children,the number of children with their fathers,mother,and both parents working out-ofhome were 334(42.47%),146(18.02%),and 320(39.51%),respectively.The ratio of smoking hehaviors among the children with their mothers working out-of-home was significantly higher than those with their father or both parents working out-of-home(8.22% vs 3.8%,χ²=9.117,P=0.003;8.22% vs 3.23%,χ²=10.504,P=0.001).The ratio of alcohol drinking once a week or more among the children with both their father and mother woking out-ot-home was obviously higher than those with father working out-of-home and those without parents working out side.(11.25% vs 6.4%,χ²=4.850,P=0.003;11.25% vs 7.67%,χ²=4.315,P=0.038).The children with their mother working outof-home had a higher ratio of fighting at least once in a term or more than those of with father working out-of-home and thsoe of without parents working out-of-home(9.57% vs 4.65%,χ²=4.312,P=0.0038;9.59% vs 6.42%, χ²=4.127,P=0.042).The children without parents working out-of-home had a lower ratio of internet surfing compared to thsoe with both parents working out-of-home(17.8% vs 28.44%,χ²=24.283,P=0.000).The results of unconditional logistic regression revealed that the influencing factors of smoking behavior were age,grade,and gender(female) with the odds ratio of 1.129,0.646,and 0.146,respectively. Conclusion Working out-of-home of hoth father and mother,especially the working out-of-home of mother,has impacts on health risk behavior and mental status of leftbehind children.