Using ethnography as an approach, this study attempts to understand how do high school students do sexual learning, construct sexual identity and do sexual practice in school life? The findings show that high school students learn and do sexuality through games, body contacts, sex talks, and doing romance. For example, by playing "Truth or Dare," the students reveal their sexual experiences and knowing of sexuality. For gay students, they play "Secret Boy Friend" to explore gay identities and homosexuality. Sex talk is the most strong way carry out heterosexuality regime. Doing heterosexuality is through the collusion of the collective sex talks and sexual morals, and this regulation presents particularly between the male peers. This study also finds that teenage girls, being seen as sex naive and be passive, in fact are great active and show the autonomy in their sexual practices and desire expression. These research findings can help current sexuality policy makers, educators and teachers to reform the curriculum and teaching of sexuality education.