Through a investigation of 546 college students, this study examined the effects of stress and social support on Internet Addiction, analyzed the moderating effects of social support and compared the differences of family support and friend support. The results showed that: (1) stress was significantly negatively related to social support and significantly positively related to Internet Addiction. Social support was significantly negatively related to Internet Addiction. (2) stress had a significant negative impact on Internet Addiction. F...