Purpose: The purpose of the study was to explore the structural relationship among school-based teacher learning community, teacher collaboration, teacher efficacy, and teacher instructional competence at Korean middle schools. The study was especially interested in examining the mediating effects of teacher collaboration and efficacy on the relationship between teacher learning community and instructional competence.
 Methods: This study drew upon 853 middle school teachers’ data from the 2021 Busan Educational Longitudinal Study, and a multi-mediating structural equation model was employed as a statistical method.
 Results: First, all of the independent variables -i.e., teacher learning community in school, teacher collaboration and teacher efficacy are positively associated with teacher instructional competency; second, the effect of teacher learning community on teacher instructional competence was mediated by both teacher collaboration and teacher efficacy; third, teacher learning community had a positive impact on teacher instructional competence through teacher collaboration and teacher efficacy in that order. Particularly, an indirect effect of the path from teacher efficacy to instructional competence was found to be greater than the indirect effect of the other two paths.
 Conclusion: Based on the findings, it is suggested that the activation of teacher learning community, the cultivation of a collaborative teaching culture, and the enhancement of teacher efficacy are necessary to improve teacher instructional competence.