Abstract: The ultrastructures of pollen grains from 20 pomegranate（Punica granatum）cultivars in Shandong Province were examined using a Hitachi S-570 scanning electron microscope. The results showed that pollen grains were tricolporate，N3P4C5 type according to Erdtman’s NPC system. They were sub-spheroidal in equatorial view，and 3-lobed sub-spheroidal or triangle in polar view. The polar axis length of pollen grains was 23.08–28.57 μm. The equatorial axis length of pollen grains was 13.07–19.74 μm. In addition，there were significant differences in some morphological aspects of pollen grains，for example，pollen size and colporate，between cultivars. Thus，it was suggested that morphological characters of pollen grains were very important for cultivars differentiation in pomegranate.

Key words: pomegranate, pollen grains, ultrastructural morphology