Abstract: Seed characteristics of 12 species representing 7 genera of Caesalpinioideae, were studied in order to define the diversity in the characters of the shape, areole, micropyle, hilum and lens as well as the testa sculpturing patterns by using both a light and Scanning Electron Microscope (SEM). The results of SEM investigation of seed coat sculpturing exhibited five distinct types of surface patterns namely; levigate, substriate, reticulate, rugulate and polygonal-discoid. Valuable taxonomic evidence has been obtained from studying the seed characteristics. Many of these characteristics are diagnostic at both the generic and specific levels.