Abstract: This paper deals with the application of the numerical method in plant taxonomical rescarch. Using Sect. Stenophora Uline as an example, interspecific variability was measured by using methods of cluster analysis. Analysis with 36 phenetic char- acters (23 external morphological, 2 cytological, 3 palynological, 5 phytoche- mistrical, 3 geographical and distributional) supports the delimitation of the 18 species as distinct taxa on the hasis of correlation coefficient and distance coeff- icient. Comparing with Pei et Tings (1979) systematic studies, similar results were found with correlation UPGMA method for cluster analysis.

Key words: application, cluster, analysis, China