It is uaually found a number of sex variant plants in the Eurya loquaiana Dunn population in Jinyun Mountain, which plants show a subdioecy characteristic. However, it is still unrevealed the gender patten, sexual evolution and adaptive mechanisms of these E. loquaiana populations. In this study, 8 sampling plots in 20 m×20 m were set in different habitats, in order to analyse the relationship between sex ratio and environmental variations, and age structure. Additionally, a sampling plot in size of 20 m×60 m was set, then the investigation of plant distribution pattern and spatial correlation between different sex plants were conducted. The results of this study indicated that (1) There were more female plants in E. loquaiana population. The ratio between female and male plants was 1.43, the percentage of sex variant plants in the studied population was 14.42%. (2) The sex ratio and percentage of sex variant plants varied in different sampling plots. Moreover, it was found that the percentage of sex variant plants positively correlated with intensity of disturbance, but negatively correlated with altitude and crown density. The reason for these findings was presumably the human disturbance. At the same time, it was discovered that the sex ratio of studied population significantly correlated with the basal diameter of E. loquaiana plants. And the sex ratio might increase with forest age. (3) On the whole, studied E. loquaiana population exhibited clumped-distribution pattern. The male plants, female plants and sex variant plants mainly randomly distributed, but in some scales, they showed clumped-distribution. (4) The male and female plants behaved the similar responses to the environmental variations. They performed positively relationship with each other in spatial distribution. The results of this study uncovered the gender pattern of E. loquaiana population and its ecological adaptive mechanisms in Jinyun Mountain.