Abstract: We used the social cognitive career theory to investigate how vocational interests affect informal learning behavior in the workplace by building a model with three different dimensions of vocational interests as independent variables and different goal orientation dimensions as mediating variables. Using a sample of 211 Chinese employees from different industries, results showed that investigative and enterprising vocational interests had positive effects, whereas realistic interests had a negative effect, on informal learning. Results also indicated that learning and performance-prove goal orientations positively affected informal learning, whereas performance-avoid goal orientations negatively affected informal learning. Further, each dimension of the goal orientation played a mediating role in the influence of vocational interests on informal learning. Findings of this study enhanced our understanding of the mechanism surrounding of how vocational interests influence informal learning and provided important new evidence for the theoretical and practical development of the relationships among interests, goals, and behaviors in the social cognitive career theory.