Abstract The characteristics of being private, interactive and active publicize sex, which used to be a taboo topic, on the Internet in every way. The group using the Internet has gradually taken an open perspective in sexual attitudes and behaviors. People are looking for short-term sex relationships through the BBS, chat rooms, and matching websites, which lead to the increasing proportion of one-night stand experiences. When people are situated in an Internet environment where sex information is open and accessible to almost everyone, will the changes in sexual attitude and behavior are also being influenced with time? It¡¦s worth further probing into the relations between the actual users¡¦ conditions and the sexual attitudes and behaviors of those who acquire sex satisfaction through the Internet. This research will be focused on the demographic characteristics, users¡¦ conditions, sexual attitudes and behaviors of average Internet users and the one-night stand group, trying to understand if different variables make differences in the users¡¦ sexual attitudes and behaviors. Therefore, in this research the independent variables are the demographic characteristics and the dependent variables are sexual attitudes and behaviors. The Internet users¡¦ conditions are the intervening variables. The researchers will collect sample data about users aged from 18 to 30, including some who used to have Internet one-night stand experiences and post messages on every BBS bulletin board, chat room, matching website and porn website. Questionnaires are designed for the users to answer on the Web. This practice took about two months altogether. 1008 questionnaires were collected. Major findings after statistic analyses are as follow: 1. The sexual attitudes of Internet users differentiate distinctly by sex. However, sexual attitudes don¡¦t change by different ages, marital conditions, education levels and occupations. 2. The sexual behaviors of Internet users differentiate distinctly in sexs, ages, marital conditions, education levels, and occupations. 3. Average Internet users¡¦ sexual attitudes make no difference in the years of using the Internet, the frequencies, and how many hours per day spent on the Internet. 4. The sexual behaviors of average Internet users change distinctly because of the different hours per day spent on the Internet, but make no difference in the years of using the Internet and the frequencies. 5. The sexual behaviors of average Internet users differentiate rather by the activeness of exposing to porn websites than by whether they are exposed to porn websites, how often, and the time spent on the websites. 6. The sexual behaviors of average Internet users differentiate distinctly rather by whether they are exposed to porn websites, the activeness, and how long on the porn websites than by how often they are exposed to the porn websites. 7. The group of Internet one-night stand is distinctly different form that of average Internet users in the years of using the Internet, average hours per day on the Internet, not in how often they use the Internet. 8. The group of Internet one-night stand is distinctly different from that of average Internet users rather in the frequencies of exposing to the porn websites and time on the websites than in the activeness of exposing to porn websites. 9. There¡¦s a positive relationship in having one-night stay experiences with the frequency of exposing to porn websites. 10. The sexual attitude of the group of Internet one-night stay are not different from that of average Internet users. 11. The sexual behavior of Internet one-night stay group is distinctively different from that of average Internet users.