This mixed-methods study investigated the sources of self-efficacy reported by Chinese undergraduate students and the related role of individual differences. One hundred and fifty-six Chinese students completed a questionnaire and open-ended responses, citing the factors that contributed to feelings of greater confidence and lesser confidence. After qualitatively coding their responses, we found that students shared diverse perspectives regarding antecedents of what made them more and less confident. Quantitative analyses revealed differences in the types and frequencies of sources of self-efficacy when considering increases or decreases in confidence, and individual characteristics such as GPA, only child status, and fear of failure. Implications for theory and practice are discussed.