Abstract:This paper reports the cluster analysis of Euphorbiaceae by using Euclidean distance-UPGMA method according to 216 taxonomic characters. The result shows that the combinations of most tribes or subtribes are basically rational, but the position of tribes, such as Galearieae, and some subtribes, such as the subtribe of Antidesmeae, can not be clustered together. Furthermore, the result of cluster does not support Webster's system at subfamily level. According to the result, a new genus Archileptopus which was not included in Webster’s system，is closer to subtribe Pseudolachnostylidinae(Phyllantheae)than to Andrachaneae.