Flowering process of Dioscorea zingiberensis C.H.Wright was observed,and pollen viability and stigma receptivity of tetraploidy and diploidy of D.zingiberensis were also compared.The results showed that the anther of D.zingiberensis had opened before male flower bloomed.Pollen viability of tetraploidy and diploidy was 59.7% and 74.9% respectively during flowering beginning period,and pollen viability was high in 24 h of flowering but reduced quickly after 36 h.Stigmas of tetraploidy and diploidy maintained a high receptivity in 24 h of flowering and then descended quickly,a part of stigmas of tetraploidy lost the receptivity after flowered 60 h.