Based on the continuous observation on located trees and branches, the phenology and sexual reproductive process of Xanthoceras sorbifolia Bunge in an annual growth cycle in Wudan area were investigated, and the relationships between fruit growth process of X. sorbifolia and effective accumulative temperature as well as the quantitative dynamics of flowers and fruits were studied. The results showed that the phenology of X. sorbifolia had a significant linear correlation with effective accumulative temperature, and there was a time sequence in the male flower silk elongating and antheral unfolding. The fruits of X. sorbifolia experienced three times of dropping during their growth process. The pollination rate was 26.4%, flower dropping rate was 73.6%, and fruit dropping rate was 92.9%, suggesting that the dropping of flowers and fruits was very serious. The fruits had a quicker vertical growth from early June to mid June and a quicker horizontal growth in the last ten-day of June, with the highest ratio of vertical to horizontal length being 2.17. The individuals of X. sorbifolia had definite differences in their phenology, which was disadvantageous to the cross pollination among the individuals, and the enhancement of pollination rate.