Abstract: In this paper ,the authors report the systematic study of pollen grains of Maloideae(Rosaceae),including Dichotomanthes,Cotoneaster,Pyracantha,Crataegus,Osteomeles,Stranvaesia,Photinia,Eriobotrya,Rhaphiolepis,Sorbus,Cydonia,Docynia,Chaenomeles,Pyrus,Malus and Amelanchier in China. The above genera have tricolprate pollen grains.The shape of grainsis subspheroidal to prolate.The pollen grains of Maloideae have the biggest size in four subfamilies of Rosaceae.The biggest one was seenin Cratagus pinnatifida with the size of (28.85-45.65)μm.

Key words: Rosaceae, Maloideae, Pollen Morphology, Systematic discussion