UGTs (UDP glycosyltransferase) are the largest glycosyltransferase gene family in higher plants, modifying secondary metabolites, hormones, and xenobiotics. This gene family plays an important role in the vast diversity of plant secondary metabolites specific to species. Experimental data of biochemical activities and physiological roles of plant UGTs are increasing but most UGTs are not still functionally characterized. To understand their catalytic specificity and function from sequence data, phylogenetic analyses have been achieved mainly in Arabidopsis, but massive and comprehensive approach covering various species has not been applied yet. In this study, we collected 733 UGT sequences derived from 96 plant species and 252 substrate specificity data. We constructed a phylogenetic tree and divided most part of these genes into nine sequence groups, which are characterized by biochemical specificity. Furthermore, we performed genome-wide analysis of seven plant species UGTs by mapping them into these groups. We propose this is the first step to understand whole glycosylated secondary metabolites of each plant species from its genome information.