We investigated and analyzed pollen morphologies of Ostericum Hoffm. (Apiaceae) of 8 species from 17 populations under light microscopy (LM) and scanning electron microscopy (SEM) in this research, in order to provide evidence for taxonomic identifications and studies of the relationship in this genus. The results showed that: (1) four types of the pollen grains from 17 populations were recognized including ellipse, subrectangular, superrectangular and equatorially constricted shapes. (2) Their shapes of equatorial view were ellipse, subrectangular, and superrectangular, and the shapes of polar view were mostly triangularrounded, while a few were triangular. (3) The polar axis length (P) is 24.7-35.6 μm, equatorial axis length (E) was 10.6-17.4 μm, P/E value and P×E^1/2 fell in 1.7-2.5 and 18.2-22.6, respectively. (4) Tricolporate apertures were observed in all the pollen grains with long and even colpus, in which most species were pleurotreme, yet a few were goniotreme. (5) Under SEM, the materials showed various exine ornamentations in equatorial regions which could be divided into three types, according to their different kinds of sculptures, as flaky cerebroid, long striate cerebroid and brevistriate baculate cerebroid. The surfaces of most grains had no appendage, except a few species contained granular or verrucous appendages. The study suggests that the pollen morphologies of Ostericum exhibited certain intraspecific stabilities both in pollen shapes and exine ornamentations, and also suggests interspecies diversities in aperture types, central protrudents and length, density and appendages of exine ornamentation. In conclusion, these morphological characteristics of pollen could probably present a potential information and significant evidence for a series of research on taxonomic revisions and genetic relationships of Ostericum.