Guided by social cognitive theory (SCT), this research investigates the structural relationships among local culture, teacher efficacy, and teachers' exercise of curricular autonomy. A total of 605 Korean elementary school teachers completed survey questionnaires that underwent structural equation modeling analysis with a phantom model approach to identify the motivational factors and their relationships. The results indicate that teachers' degree of internalization of mainstream Korean culture and teacher efficacy influence their implementation of the reform agenda, while teacher efficacy mediates the effect of culture. Theoretical and practical implications for scholars, policy-makers, and practitioners are provided.