Abstract: A numerical taxonomic study on genus Salix L. of China(Ⅰ) is presented. At first, 37 operational taxonomic units(OTU's) were chosen according to 37 sections of Chinese Salix(Wang & Fang et., 1984), each section were represented in it's type species or primitive species (table 1). After removed the correlation and homology among all Salix characters, 32 morphological characters including four deriative characters were employed. Through standardization for original data matrix,we used the coefficients of correlation (r_ij) and distance (d_ij)as similarity measure and utilized several cluster analysis methods Being of comparison of the cophenetic correlation coefficient r_es values, UPGMA method were selected as the optimal one and it's result taked shape phenograms, figure 1, figure 2. On the basis of figure 1 and figure 2, 37 sections of Chinese Salix form seven greater sections. The order from A sectionto G section shows evolutionary process. Particularly, the relationships among 37 sections are our primary results. We found and explained some problems about morphological classification, divided and merged many sections, such as a few of the primitive sections in the A section, 10 Sect. Floccosae Hao and 11 Sect. Lindleyanae Schneid., 22 Sect. Hasatatae A.Kern. and 23 Sect. Arbuscella Ser. ex Duby, 7 Sect. Fulvop-ubescentes C. F. Fang and 25 Sect. Lanatae Koeh., 14 Sect.Eriocladae Hao and 9 Sect. Denticulatae Schneid., 8 Sect. Magnificae Schneid., and so on. On numerical method, we discussed and evaluated the distance coefficient. The combined line (Xu et., 1983) were satisfactorily applied to divide the taxa.