By using nested analysis,principal component analysis,correlation analysis and cluster analysis,we studied the phenotypic diversity,phenotypic variation and the relationship between phenotypic variation and microenvironment of the 21 phenotypic traits in 8 populations of Acer grosseri in Shanxi.The results revealed that:(1)There were significant differences in genetic variation in all phenotypic traits among populations and within population.The mean phenotypic differentiation coefficient (V_ST）was 50.16%,which was approximately equal to that within populations(49.84%).Coefficient of variation (CV) of all traits was from 7.89% to 37.04%,with the average of 19.74%.The seed traits of A.grosseri were stable than fruit traits and leaf traits.Shannon-Wiener information index was 1.692 3,which indicated that there was high phenotypic diversity in A.grosseri.(2)The correlation analysis showed that the phenotypic variation within populations appeared gradient regular changes,the shape of leaf blade from long ovate to broadly ovate shape,while fruits and seed got smaller with the rise of elevation.(3)The 8 populations of A.grosseri investigated could be divided into two groups according to the UPGMA cluster analysis,the phenotypic traits gather on the basis of geography distance.In summary,there is vast variation within the species of A.grosseri which was relevant to biological characteristics and distribution of the habitat.