Abstract:Bretschneidera sinensis Hemsl., a monotypic species and Tertiary relict tree, is listed in the State First-Class Protection Tree Species of China. The natural population is decreasing nowadays with a sparse distribution ranged from south China to northern Vietnam. Within this study, we investigated the flowering behavior, pollen type, dynamic viability and storage method of pollen and receptivity of stigma. The elongation of the stigma at initial flowering stage was observed, which leads to the physical barrier compromising the self-pollination effectively. The receptivity of stigma developed form little bud to full-bloom stage, and mucilage was secreted by stigma only at full-bloom stage. Pollen grains were starchless which indicate a typical insect pollination. The viability of pollen was very low at bud stage, and then reached high at full-bloom stage. The optimal concentration of sucrose solution for in vitro germination was 20%. Pollen grains were observed to be sensitive responding to storage treatments. Pollen viability could be maintained up to 190 h under freeze storage (- 20 ℃), suggesting that low temperature is the key factor to reserve the pollen viability. The resistance of the wild population upon climate change was quite fragile because the time-frame on the flowering of natural populations of B. sinensis was short. Thus, collection and low-temperature storage of mature pollen in combination with artificial pollination are recommended in B. sinensis.