相似性系数的正确理解和运用,对植物区系地理学中的植物区系分区、过渡区的植物区系地理属性及植物区系起源演化都具有重要的理论意义。文中通过相似性系数、种相似性系数、属相似性系数和科相似性系数等术语的阐述,提出了"区系相似性系数(Coeficient of simi-larity of flora)"概念。简要介绍了属或种(或科)相似性系数在应用中存在的问题和解决的办法。并建议在植物区系地理比较研究中采取统一、科学的计算公式。

It is the most important in Floristic Geography to determine floristic region,geographical features of transitional floristic region and evolution of flora by correcting and using the coefficient of similarity.The author has commented the formulas and definitions of different coefficient in floristic research,gives the definition of the coefficient of similarity of Flora,introduces exit problems and solved the way in application of coefficient of similarity to floristic geography in the Paper.It is suggested that adopting a same and scientific mathematical formula S C=2c/(A+B)×100% in the comparison study of floristic Geography in the future.