The sex ratio, spatial distribution, as well as the correlation of Ephedra rhytidosperma have important effects on dioecious plants reproduction, evolution, and development. E. rhytidosperma is a national second-class protective plant with narrowly distribution, which is dioecious and plays an key role in maintaining the stability and diversity of Helan Mountain desert ecosystem. But research on the sex ratio of E. rhytidosperma populations has not been reported yet. In this paper, the sex ratio, spatial distribution and spatial correlation of E. rhytidosperma in the Helan Mountain were analyzed at four different elevations (S₁, S₂, S₃, S₄). Our results showed that:(1) the sex ratio of E. rhytidosperma was closely related to its environmental conditions. The four populations at different altitudes were male-biased, S₃ and S₄ in harsh growing environment were significantly male-biased at younger period (P<0.05), and there also existed male tendency at the adult and old ages; Analysis of different age groups showed that male bias occurred at different stages due to environment. For S₁ and S₂ in favorable conditions, there was a significant or tendency of female-favoring in young and adult stage, while male-favoring occurred in an old stage. (2) The spatial correlation between male and female populations would determine the development. For S₁,S₃,S₄, male and female spatial correlation showed a trend from"positive-correlation→to no-correlation". But the spatial correlation of S₁ was of insufficient relevance and far less than that in S₃ and S₄, so it was declining. While S₃ and S₄ were growing. It shows that the wider spatial correlation is good for reproducing. However, the populations of S₂ were uncorrelated, the male and female populations developed separately and they were independent, and lack of larvae, so it was declining. The results of the study respectively revealed the composition, structure, spatial distribution of E. rhytidosperma, The paper also provided theoretical basis for E. rhytidosperma-conservation.