The phenotypic diversity of 6 populations of Rosa platyacantha in Eastern Tianshan mountains of Xinjiang were analyzed based on 11 phenotypic traits from leaves, flowers, fruits and seeds. The results showed there were significant differences in phenotypic traits both among and within populations. The mean phenotypic differentiation coefficient (VST) of 11 morphological traits among populations was 27.50%, indicating a more abundant phenotypic diversity within populations than among populations. The average variation coefficient (CV) of phenotype traits with 16.51% showed there was relatively lower variation of phenotypic traits in the populations. Both the Duncan’s test of CV and the principal component analysis of phenotypic traits indicated the traits involved fruits and seeds were the main factors account for phenotypic variations. Correlation analysis further showed there was no significant correlation between vegetative and productive traits. The cluster analysis showed six populations were not clustered according to geographic distances but due to the interaction of genetic variation and environmental factors, especially altitude here.