Breast cancer has become the most prevalent cancer among women, and posed a significant health threat worldwide (WHO, 2019; World Health Organization, 2019). Over the past decades, China has witnessed a dramatically increasing breast cancer incidence. An estimate of 268,600 Chinese women were diagnosed of breast cancer and 69,500 were died in 2015, accounting for 15.1% of new cancer cases and 6.9% of cancer deaths in women (Chen et al., 2016). In response to the high incidence, Chinese government had started to launch several large-scale breast cancer screening programs in the recent years (Song et al., 2015; Wang et al., 2019). However, Chinese women still have a lower screening rate for breast cancer, when compared to those in the U.S. and Europe. Numerous health communication studies have highlighted the importance of factual knowledge as an antecedent to health behavior. Thus, it is important to examine the antecedents of knowledge. The central purpose of this study is to examine how news attention on traditional media and social media, and reflective integration (i.e., interpersonal discussion and elaborative processing) affect Chinese women’s breast cancer knowledge. Several hypotheses were developed and tested using online survey data from 821 young women in mainland China. Items in the questionnaire were adapted from past studies and were translated from English to Mandarin. Data were analyzed using Pearson correlation and hierarchical regression analysis in IBM SPSS Statistics 21. Regression results show that news attention on social media (β = .14, p < .001) is significantly associated with young Chinese women’s breast cancer knowledge. This suggests that Chinese women who pay more attention to news on the social media tended to have higher level of knowledge towards breast cancer. However, no significant association was find between news attention on traditional media (i.e., newspaper and television) and breast cancer knowledge. Regarding reflective integration process, our regression results show that elaborative processing (β =.07, p < .05) is positive associated with young Chinese women’s breast cancer knowledge, whereas interpersonal discussion had no significant effect on it. This suggest that respondents who actively process and synthesize information tend to have a higher level of breast cancer knowledge. The results may help health professionals to develop a more comprehensive and effective strategy to increase breast cancer knowledge for this group of people. Theoretical and practical implications will be discussed.