Background: Internet Addiction is a newly emerging issue for adolescents globally. Previous literature suggested a tangled relationship between Internet Addiction, depressive mood and lower subjective and objective ratings in Quality of Life. However, the independent relationship between Internet Addiction and Quality of Life was less discussed. Method: A cross-sectional study was conducted in Shenzhen adolescents to address the independent associations between Internet Addiction and 4 domains of Quality of Life (physical, psychological, social relation and environmental domains), in order to further guide the prevention and intervention for IA. Associations were calculated using linear regression models before and after the adjustment for the existence of depressive mood and confounding demographic factors. Result: The prevalence of Internet Addiction in Shenzhen was 23.2%. Engaging with Internet Addiction resulted in significant decrease in Quality of Life score in physical domain (B = -0.87, p<.001) and psychological domain (B = -0.40, p = 0.011) as well as insignificant decrease in social relation domain (B = -0.36, p = 0.063) and increase in environmental domain (B = 0.02, p = 0.906). Conclusion: Although Quality of Life is considered to be related to many factors, Internet Addiction on its own had a significant impact on lower subjective life satisfaction overall, especially in psychical and psychological wellbeing. Key Words:Internet Addiction, Quality of Life, Adolescents, Depressive mood, Chinese