This article takes Bradford's law as the frame of reference, chooses keywords or thesaurus as measure unit and obtains data from large scientific databases, on the above-mentioned basis studies the scattering distribution of scientific information. 文章以布拉德福文献分散定律为参照系,选择文献中的关键词或主题词作为计量单元,从大型数据库中输出数据,在微观层次上研究科学信息离散分布的规律。