China boasts one of the largest adolescent populations in the world, with 165 million in total (United Nations, 2017). In recent decades, Chinese adolescents have reached sexual maturity at increasingly early ages, and more and more young people in China are open to premarital sex while at the same time they general lack sexual and reproductive health knowledge and awareness of safe sex. In light of this situation and the risks adolescents face in terms of sexually transmitted infections (STIs), unintended pregnancies, abortions and sexual and gender-based violence, education about sexuality is of utmost importance. This publication describes the findings of a study that aimed to understand the status of the implementation of sexuality education in Chinese middle schools. The study surveyed key stakeholders, including students, teachers and principals, education officials and other educators, seeking to understand how they receive or provide sexuality education, as well as their perceptions of and attitudes to school-based sexuality education. This publication also provides a summary of policies and good practices and identifies gaps in light of the study, on the basis of which it offers practical recommendations for further improvement of school-based sexuality education in China. The study, the largest of its kind in China so far, adopted a cross-sectional design that integrated quantitative and qualitative approaches. It sampled 30 middle schools across six provinces and municipalities in China that claimed to have sexuality education in place. A total of 4,737 students, 151 teachers and 29 principals from these schools participated in the survey. The study collected quantitative data through digital and printed questionnaires, and compiled qualitative information through in-depth interviews. [The publication is the result of a study conducted by the Shanghai Institute of Planned Parenthood Research (SIPPR). Translated by Dandan Chen.]