To reveal the the complex relationships between the characteristics of interspecific associations and communities succession in the succession process of pine oak forests community on the south-facing slopes in Qinling Mountains. Based on 2?2 contingency tables, we used the Variance Ratio, χ2 test and Jaccard index and Spearman’s rank correlation coefficient to study the characteristics of interspecific association and correlation among main plant populations of different successional stages in the successive serials from Pinus tabulaeformis forest to P. tabulaeformis-Q. aliena var. acuteserrata mixed forest then to the subsequent Quercus aliena var. acuteserrata forest on the south-facing slopes in Qinling Mountains. The results showed that: (1) The overall interspecific associations of dominant species in Pinus tabulaeformis forest, Quercus aliena var. acuteserrata forest and Pinus tabulaeformis-Quercus aliena var. acuteserrata mixed forest are significant positive connection, each communities has a relative stability. (2) The positive and negative interspecific associations and correlation percent of main species in Pinus tabulaeformis forest and Pinus tabulaeformis-Quercus aliena var. Acuteserrata mixed forest is smaller, and their community stability are inferior to Quercus aliena var. Acuteserrata forest.(3)Interspecific competition Among pioneer species, pioneer species and prior transitionary species, climax species, post transitionary species and climax species is more intense, but there are more positive connection among the transitional species(including prior transitionary species, prior transitionary species and post transitionary species, post transitionary species) ,and the interspecific relationship is more stable relatively. (4)The main species in different succession process of pine oak forests community are respectively divided into 4, 5, 4 ecological groups. Above all, the interspecific relationship of main species in the succession process of pine oak forests community on the south-facing slopes in Qinling Mountains gradually become stable and concomitant. In practice, the reasonable adjustment measures of interspecific relationship can prompt the pine oak forests community on the south-facing slopes in Qinling Mountains more stable and healthier, effectively shorten the process of succession.