In this study, we evaluated the phenotypic diversity of 40 natural populations from 3 species (O. kokonoricus, O. thoroldii and O. intermedius) of Orinus using 22 phenotypic traits. According to index of VIF, we filtered altitude (ALT) and 9 climatic factors like mean annual precipitation (MAP), adopted dbRDA analysis (Distancebased redundancy analysis) to explore the relationship between multigeographical climatic environment and phenotypic diversity of different species of different populations, to investigate the mechanism of plant phenotypic diversity of Orinus. The results showed as follows: (1) based on ward clusting of 22 traits, it generated 2 clusters at ward 55 by squared error of within populations, and the spatial autocorrelation among populations were not significant (P > 0.05). Our results showed that its pattern responded to the habitats was unique, the ShannonWiener (H) index of 17 qualitative traits ranged from 1.045 to 2.734, the average coefficient of variation was 47.84%, the color of spikelet was the lowest phenotypic diversity among populations (H: 0.170). (2) Nested analysis of variance revealed that both within and among populations are abundant variation (F > 10, P < 0.01), principal component analysis also showed that flag leaf and glumes and lemmas traits were important components of total variation, indicating the variation of phenotypic traits among populations (71.10%) was much greater than that within population by V_st(28.90%). The phenotypic variations derived from intrapopulations of Orinus. (3) Furthermore, dbRDA proved that ALT and annual mean wind speed were crucial factors for driving the phenotypic dissimilarity between O. kokonoricus and O. thoroldii populations, and extreme climate promoted phenotypic similarity like mean temperature of driest quarter (Bio9) and precipitation of driest month (Bio14) among populations, inversely aridity index (AI) and vapor pressure (Vapr) promoted effects of phenotypic dissimilarity. Phenotypic variation of O. intermedius populations were limited by MAP, potential evaporation (PET) and Vapr. Phenotypic variance of Orinus accounted for a lot of tendency along geographic and climate change among populations, were remarkable indicators for environmental suitability of alpine plant.