This study focused primarily on the biodiversity of microbial communities in soil between the rhizosphere and non-rhizosphere in summer and autumn among four types of common trees-the Tooth Oak (Quercus aliena var. acutidentata), Chinese pine (Pinus tabuliformis), armand pine (Pinus armandii) and spruce (Picea asperata)-on the Qinling Mountain, China, using the micro BIOLOG method. We found that:(1) The Average Well Color Development (AWCD) of the soil in the rhizosphere was significantly different from that in the non-rhizosphere in most of the seasons, with AWCD in the non-rhizosphere being higher than that in the rhizosphere, except for the soil where spruce was grown in autumn. (2) Biodiversity of microbial communities differed remarkably between rhizosphere and non-rhizosphere in the soil where the four different types of trees were grown in either summer or autumn. For soil where tooth oak was grown, the biodiversity of microbes in the rhizosphere was lower than that of the non-rhizosphere in both summer and autumn, and both these values were in lower in summer than in autumn. While the biodiversity of microbes in soil among the other three coniferous trees showed similar trends to that of tooth oak in summer, they exhibited the reverse of this trend in autumn. Furthermore, the biodiversity of these soils in autumn was lower than that in summer in the non-rhizosphere but higher in the rhizosphere. (3) The results of principal component analysis indicated that the biodiversity of microbial communities in the soil for these four types of trees was significantly different, and the principal component scores for biodiversity among the four studied species in either the rhizosphere or non-rhizosphere in different seasons also varied substantially. The highest score among all studied species was found in the non-rhizosphere of the soil where tooth oak grew, followed by that of armand pine, and spruce, with that of Chinese pine being the least. The principal component score for the soil in the rhizosphere varied with season-in summer, the score was relatively high for Chinese pine and armand pine and lower for spruce. In autumn, the score was relatively high for Chinese pine and spruce and lower for tooth oak. The correlation between the comprehensive score and biodiversity index in all cases was positive or extremely positive. (4) Redundancy analysis showed that the combined effects of soil properties have a significant impact on the biodiversity of microbial communities in the soil.