Objective: To explore relationship between self-control and health risk behavior among orphans in middle schools. Methods: A total of 415 orphans and 352 non-orphans in middle schools were selected from Hunan, Liaoning, Sichuan, Guangdong and Fujian during Oct. 2017 to Apr. 2018. All the participants were surveyed with the Adolescent Health Related Risky Behavior Inventory (AHRBI) and the Self-Control Scale (SCS). Results: All the orphans in ordinary middle schools obtained significant higher scores in AHRBI (1.76±0.70) than students in orphan schools (1.55±0.40) and non-orphans (1.50±0.37) (P<0.01). Students in orphan middle schools showed significant higher scores in SCS (3.37±0.56) than orphans in ordinary middle schools (3.07±0.63) and non-orphans (3.13±0.60) (P<0.05). Selfcontrol of orphans was significantly associated with 44% lower risk of health risk behaviors (P<0.05). Conclusion Self-control could be seen as a protective factor for health risk behaviors among orphaned children and adolescents. The environment of orphan schools is beneficial to the development of self-control, and thus helps preventing health risk behaviors among orphaned children.