To determine the effect of different coniferous plantations on the soil characteristics and diversity and community structure of soil microorganisms, Illumina MiSeq high-throughput sequencing and OTU analysis were used to assess the structure of the microbial community in Larix gmelinii and Pinus koraiensis forests in the Baishilazi Nature Reserve (LGe, PKe) and the experimental forest farm of Liaoning Institute of Forest Management (LGd, PKd) in the montane region of eastern Liaoning Province, China. Soil physiochemical properties were determined to analyze the relationship among bacterial community structures, forest types, and soil environmental factors. Ours results showed that (1) soil total carbon, total nitrogen, and available nitrogen contents in LGe was not significantly different from Pke, and LGd was significantly (P < 0.01) higher than PKd; (2) 34 different bacterial phyla were identified in the soil of L. olgensis and P. koraiensis forests in this area. The dominant bacterial groups were Proteobacteria, Actinobacteria, Acidobacteria, Chloroflexi, Verrucomicrobia, and Gemmatimonadetes; (3) structurally, there was no significant difference in diversity and richness indexes between LGe and PKe. The diversity indexes of the soil microbes in LGd were significantly higher than that in PKd, and there was no remarkable difference in richness indexes between them. The results of the Metastats analysis showed that the number of significantly different phyla and genera between LGe and PKe were relatively few, exhibiting a converging trend, than that of LGd and PKd; (4) redundant and correlation analyses indicated that soil pH, TN, AN content, and C/N were the main factors that correlated with microbial community structure of coniferous forests in this region. We concluded that planting L. gmelinii had no significant difference in increasing soil nutrients and improving bacterial community structure with P. koraiensis in Baishilazi Nature Reserve. However, L. gmelinii was remarkably more conducive to soil nutrient accumulation than P. koraiensis in the experimental forest farm.