Abstract: Based on the datasets from the field, 2×2 contingency table, the interspecific relationships among 24 dominant populations of Platycladus orientalis communities in Yanshan nature Reserve in Shanxi were studied by using variance ratio(VR) test, Fisher’s exact test, Jaccard’s association index and Spearman rank correlation coefficient. The results indicated that the overall association of the community was not significant (p>0.05) and tended to no correlation among all species, and it meant that the species of the community were mostly independently distributed. The combination of Fisher exact test and Jaccard’s association index in the study obtained a better result. The results of Jaccard’s association index showed that the association intensity of species pairs between the main dominant populations of each layer was more significant. The results also showed that the dominant populations of P.orientalis communities could be divided into three biological groups: Pinus bungeana group, P.orientalis group and Artemisia sacrorum group.

Key words: Platycladus orientalis communities, dominant populations, interspecific relationships, Yanshan nature reserve