The purpose of this study was to investigate the effects of teachers' perceived school principals' instructional leadership on school organizational culture and school organizational effectiveness. The method of the study was a literature and a survey. The subjects of this study were a stratified random sampling of 1,374 members at elementary school teachers working in Seoul, Incheon and Gyeonggi. Measure instruments used in this study were three questionnaires: school principals' instructional leadership, school organizational culture, and school organizational effectiveness. Statistical analysis was used correlation and regression analysis. The findings of this study were as follows : First, it was found that the school principals' instructional leadership had a positive correlation on school organizational culture and school organizational effectiveness Second, it was found that the school principals' instructional leadership had an influence on school organizational cultures. Specific results were in the following order : instructional evaluation activities .404, instructional supporting activities .216, school vision proposals .196, instructional improvement activities .087. Third, it was found that the school principals' instructional leadership had an influence on the school organizational effectiveness. Specific results were in the following order : instructional supporting activities .298, instructional evaluation activities 213, instructional improvement activities .143, school vision proposals .107.