This paper has investigated the changes of American high and primary school size in the visual angle of small-scale school destiny during the reform of different historical periods of school, and then analyzes important meaning, appropriateness and limit of influence of school size. 本文以美国小规模学校在不同历史时期教育改革中的命运为视角,考察了美国中小学尤其是中学规模的变迁,由此来分析学校规模的重要意义、变化的基本规律及其影响的有限性。