Acer ginnala (Aceraceae) is a multipurpose shrub with significant economic and ecological value in China. Considering the fact that various natural and anthropogenic pressures might bring about serious influences to morphological diversity of Acer ginnala. In this context, thirty-four phenotypic traits were analyzed to explore the phenotypic variation and pattern of 19 Acer ginnala populations by principal component analysis (PCA), nested analysis and cluster analysis. A correlations between phenotypic traits and environment factors were used pearson's correlation coefficient. The results showed that phenotypic traits were significantly different among 19 populations. Phenotypic variation coefficient (CV) and Shannon-Wiener index (HSW) were 23.53% and 5.22 respectively. The phenotypic differentiation coefficient (Vst) among populations was 56.996%, which was more than that of within populations (43.004%). The total of four principal components was 87.30% in principal component analysis. Nineteen A. ginnala populations were divided into two groups based on cluster analysis. Absolute high temperature and Annual average temperature were negative correlated to leaf length of A. ginnala, while Annual precipitation had a positive correlation with length/width ratio of leaf. Environmental factors would affect the phenotypic variation and pattern of A. ginnala populations.
