Abstract: The reproductive allocation (RA, the ratio of flower biomass to total aboveground biomass) of Oxyria sinensis Hemsl., a clonal dioecious perennial, was compared among five populations along an altitudinal gradient from 1978 m to 2780 m. The goal of this study is to answer the following questions: (1) What is the variation in the reproductive allocation of O. sinensis? (2) Does variation in reproductive allocation correspond to an altitud-inal gradient? (3) Is the reproductive allocation of male and female O. sinensis correlated to environmental fac-tors? We found that reproductive allocation to ramets decreased with increasing vegetative biomass in both male and female plants. Increasing altitude corresponds to a decrease in height of ramets, total aboveground biomass, and biomass of vegetative organs in both male and female plants. The total aboveground biomass of male ramets was significantly higher than female ramets in the populations at the altitudes of 2422 m and 2780 m. The biomass of flowers and reproductive allocation of male ramets were significantly higher than of female ramets at all popu-lations except at the lowest altitude population, which indicated male ramets allocate more biomass to reproduc-tion than female ramets. Our results do not support the idea of an invariable minimum vegetative biomass for reproduction, probably because resource can be shared among ramets within one ramet system of a clonal species, and the pattern of RA in O. sinensis might be an adaptation to the unpredictable rain and decreased pollinator visitation in the higher altitudinal populations.