Abstract:The seeds of 15 species (33 samples) of the genus Illicium Linn. were observed under light microscope and scanning electron microscope, and described. The results indicate that Illicium seeds are obovoid, rarely ellipsoid or ovoid, flattened. Exotesta is stone-hard, mesotesta coriaceous, endotesta membranaceous. Exotesta is yellowish, egg-yellow to orange-brown with invariably smooth and lucidly ceraceous layer, without testa ornaments found. Seed has a raised longitudinal ridge (raphe) at the ventral surface extending from the hilum to the top. Hilum locates at the bottom, near ventral surface of seed, or at the bottom of seed, ovate or elliptic, depressed. Embryo minute, endosperm copious, oily. The most features of seed surfaces among the species of Illicium are similar and constant, which supports that the genus should be relatively natural monophyletic group.