Despite the high breastfeeding initiation rate in China (> 90%), the low exclusivity rate is of concern. Some traditional behaviors, combined with increasing popularity of infant formula, may negatively affect future breastfeeding rates. As suggested by the theory of planned behavior, understanding breastfeeding beliefs of young adults may help identify and address misperceptions of future parents, supporting maintenance of the current initiation rate while increasing rates of exclusivity and duration. No research has evaluated these factors among young adults in Mainland China. The objective was to explore any relationships between breastfeeding knowledge, attitudes, previous experiences, and future intention among undergraduate students in Mainland China. This was a cross-sectional, quantitative study conducted from May to June 2012. A convenience sample of 395 students from a major public university in southwest China participated in the survey. Breastfeeding knowledge was moderate (76.7% of total score), and breastfeeding was considered to be painful (34.2%), to make breasts sag (43.1%), and to restrict the freedom of mothers (52.5%). In addition, 58.2% of students reported that they would feel embarrassed if they or their partners were to breastfeed in public, and acceptability of breastfeeding in public was low (34.7%). Three-fourths of the students (75.1%) expressed future breastfeeding intent, though males were more likely to report this intention (ie, to support a partner in breastfeeding) than were females (81.3% vs 71.7%, P = .04). To create a more breastfeeding-friendly culture, future research is warranted to explore these negative beliefs about breastfeeding and to counter misunderstandings among future parents in Mainland China.