Abstract: Flexistyly is a novel flowering strategy occurring in ginger family(Zingiberaceae).It is an unique and "active" floral dimorphism achieved by both changing the position of the stigma and separating the maturation of male and female organs in different times during anthesis.In this research,outcrossing rates of two species(Amomum maximum and A.putrescens) with flexistyly and one species(A.villosum) without flexistyly were compared using allozyme experiments.The results show that the outcrossing rates of flexistylous species are significantly higher than that of the species without flexistyly.Moreover,within the natural populations of flexistylous species, outcrossing rates of anaflexistylous morphs are higher than that of cataflexistylous morphs.These findings demonstrate that flexistyly may play an effective role to promoting outcrossing.