In this paper, sexspecific differences in flowering phenology and floral morphology of Humulus scandens were tested using a pot experiment under watercontrolled condition. Obvious differences between the male and female individuals were observed in response to different water regime. Drought stress induced Hscandens population to flower earlier and last longer. Compared with males, flowers of female opened earlier. Moreover, inflorescence axis length, inflorescence axis diameter and anther length in droughtstressed males were significantly reduced 2481%, 2907%, and 514% (P<0001, P=0003, P=0024), respectively. Concomitantly, pollen quantity and the pollen vitality were also decreased significantly. In contrast, the inflorescence axis length, style length and average number of flowers per inflorescence in droughtstressed females were increased 978%, 7062%, and 5704% (P=0039, P<0001, P<0001), respectively. Furthermore, the seed length, and seed width, singleseed weight, and 1000seed weight under drought stress were significantly reduced 1212%, 1259%, 4343%, and 1538%, respectively (P<0001). On the other hand, compared with contrast, the aboveground biomass decreased significantly in both male and female Hscandens individuals under drought stress (P=0002, P=0020). However, the reproductive investment of females was significantly higher than males under drought stress (P=0049). In a word, effects of drought stress on flowering phenology and floral organs are significantly different between two sexes. To alleviate the negative influences on reproductive ability caused by drought, females of Hscandens individuals may allocate more biomass to reproductive organs than males under drought stress.