Interspecific plant associations, which are significant quantitative and structural characteristics, reflect relationships among species in a plant community as well as community stability, and they have important theoretical significance and application values for the restoration and reconstruction of vegetation, protection of biodiversity, and sustainable utilization of the plant community. For understanding the mechanisms underlying the formation of interspecific associations in Pterocarya stenoptera communities, the interspecific associations of the main woody plants in a riparian Pterocarya stenoptera community near Lijiang River were examined. A total of 20 sample plots were set up and investigated in the studied area. We selected 8 tree-layer species and 18 shrub-layer species on the basis of importance values, and quantitatively researched interspecific associations and correlations by using a set of methods, namely, variance ratio analysis of the overall association, χ² test, Pearson's correlation coefficient test, Spearman's rank correlation coefficient test, and principal component analysis (PCA) based on 2×2 contingency tables of species presence/absence and abundance per quadrat data. The results showed that the overall interspecific associations were non-significant, positive correlations among the main plant populations in the tree layer, shrub layer, and combined tree and shrub layer, and this reflected that the Pterocarya stenoptera community in the riparian zone of the Lijiang River is at a relatively stable developmental stage. The results of the χ² test showed that a vast majority of the species pairs were not significantly associated, reflecting a weak association among the various species pairs in the tree layer and shrub layer; most of the species showed an independent distribution pattern. Pearson's correlation coefficient and Spearman's rank correlation tests showed that the significance rates of the species pairs in the tree layer, shrub layer, and combined tree and shrub layer were lower, and the species pairs with insignificant interspecies correlations accounted for the majority of the species pairs in the tree layer, shrub layer, and combined tree and shrub layer. The results of the χ² test, Pearson's correlation coefficient test, and Spearman's rank correlation coefficient test were consistent; however, Spearman's correlation coefficient test was more sensitive than the χ² test and Pearson's correlation coefficient test, and could make up for the limitations of the χ² test and Pearson's correlation coefficient test. Therefore, it is better to investigate the interspecific association and correlation by combining the χ² test with Pearson's correlation coefficient and Spearman's rank correlation coefficient tests, because this approach can more accurately and reliably reveal the intrinsic relationship of interspecific associations and correlations among the plant species. According to the PCA and evaluation of interspecific relationships, the 20 main species in the tree and shrub layer were divided into four ecological species groups.