Social anxiety was compared between online and real-life interaction in a sample of 2,348 college students. Severity of social anxiety in both real-life and online interaction was tested for associations with depression, Internet addiction, Internet activity type (gaming versus chatting), and scores on Behavioral Inhibition System (BIS)/Behavioral Activation System (BAS) scales. The results showed that social anxiety was lower when interacting online than when interacting offline. Depression, Internet addiction, and high BIS and BAS scores were associated with high social anxiety. The social anxiety decreased more in online interaction among subjects with high social anxiety, depression, BIS, and BAS. This result suggests that the Internet has good potential as an alternative medium for delivering interventions for social anxiety. Further, the effect of BIS on social anxiety is decreased in online interaction. More attention should be paid for BIS when the treatment for social anxiety is delivered online.