Abstract: This paper reported the result of classifying 22 breeds of Lysimachia growing in Fujian province with the systematic clustering method which is in accordance to the basic principle of quantitative classification. 56 selected morphological features of 22 breeds of Lysimachia are clustered by computer to study their interspecific affinity. The result indicated that the use of computer in clustering analysis is comparatively an ideal means for plant classification. The.result of clustering analysis by computer is basically identical with that of traditional classification, and this method is a feasible one that provides some scientific basis for further research on plant classification.