本研究旨在探討國中校長教學領導、學校知識管理與教師教學效能之關聯性。在分析校長教學領導對教師教學效能之影響時，係同時採取直接及中介效果模式之觀點，從事多層次之分析。研究使用調查研究法，針對臺灣地區之公立國民中學教師進行問卷調查，總計回收75校共1032份有效問卷。所得資料主要利用多層次結構方程模式進行統計分析，結果共得到三項結論：(1)校長教學領導、學校知識管理、與教師教學效能彼此間具有正向的關聯。(2)就直接效果模式而言，在教師層次上，校長教學領導可正向影響教師教學效能；在學校層次上，校長教學領導對教師教學效能未具影響力。(3)就中介效果模式而言，在教師及學校層次上，校長教學領導皆可間接透過學校知識管理之中介作用，間接正向影響教師教學效能。 Results drawn from earlier researches support instructional leadership of principals exercise a measurable effect on teaching effectiveness of teachers. However, the conceptual and methodological tools have created discrepancies in research results. The use of directed-effects and general single-level SEM model do not resolve the most important theoretical issues concerning the means by which principals achieve an impact on teaching effectiveness and how contextual forces influence the exercise of instructional leadership in the school. By using the Multilevel Structural Equation Model, this study examined the relationship between principal’s instructional leadership and teaching effectiveness mediated by the condition of school knowledge management. Three related questionnaires were used to measure the major variables while data collected from a sample of 1032 teachers in 75 junior high schools in Taiwan. It was found that instructional leadership has significant direct effects on teaching effectiveness in the individual (teacher) level but not in the school level. However, tested by the mediated-effects model, it was found that instructional leadership has significant indirect effects on teaching effectiveness mediated by the school knowledge management both in the individual and school level.