A metrical way of pollen activity by pollen germination in vitro was adopted to evaluate effect of dehydration on pollen activity of platycodon grandiflorum. Seed setting of pollen after the treatment of the dehydration and storage was estimated by artificial pollinating. This paper was given the base for storing pollen . The results showed that the pollen germination were better at 25℃~40℃, and it were best at 30℃ for 1.5 hours. Germination and tube length of pollen decreased after the treatment of the dehydration, with the smallest decline of pollen activity after treatment of dehydration in oven for 1.5 hours to 2 hours. furthermore, storability of pollen after treatment of dehydration in oven for 2 hours was longest than other treatments, its germination rate of pollen after five days under normal temperature was 42.9 percentage and its tube length of pollen was 192.3 micron. Changes of seed setting of pollen after different treatment were different significantly. Seed setting of pollen with treatment of dehydration for 2 hours in the shade was lowest, and seed setting of pollen was almost same with treatments for 6 hours in desiccator, for 2 hours in the sun and for 1.5 hours in oven. Seed setting of pollen were decreased with the delaying of storage time, and seed setting of pollen with treatment for 1.5 hours in oven after 5 days under normal temperature was 11.5%, and its seed setting was higher than others significantly.