The Internet has gained great popularity among Chinese college students, but studies on Internet use behaviors and their relationship with sexual risk perception and behaviors have been limited. A survey was conducted among 1,845 college students in an eastern province of China, in order to assess the pattern of Internet use among Chinese college students, to examine the relationship of Internet use and HIV knowledge and susceptibility, and to explore the relationship of online risk behaviors with sexual status, sexual intention, and sexual perceptions. Data suggest that many students used the Internet frequently and often spent long hours online. Differences between genders and across grades were observed in the patterns of students' Internet use. Male students reported much higher rates of visiting pornographic websites or engaging in other online risk behaviors. Students' HIV knowledge or susceptibility did not differ by the extent of Internet use, but online risks were positively associated with their sexual status, sexual intention, and sexual perceptions. Students who were sexually active, planned to have sex, or possessed permissive attitudes toward pre-marital sex were more likely to report online risk behaviors such as visiting pornographic sites, cyberbullying, or distributing erotic materials via the Internet. The data underscore the importance to provide students with appropriate guidance on their Internet use, especially for reducing online risks and utilizing Internet as a source for sex education and HIV prevention.