Broad-leaved Korean pine mixed forest is a kind of zonal climax vegetation with ecological significance in Northeast China, whereas Changbai Mountain is an ideal area to study the effects of precipitation variation on temperate forest. Taking the virgin broad-leaved Korean pine mixed forest in Changbai Mountain as the object, and based on T-RFLP method, this paper analyzed the spatial heterogeneity of fungal diversity in 0-5 cm and 5-10 cm soil layers and in rhizosphere soil at three different precipitation plots (30% increase, 30% decrease, and the control). Both the increase and the decrease of precipitation increased the diversity of soil fungi, but the dominant population changed. In 0-5 cm and 5-10 cm soil layers, the T-RFs over 500 bp increased with precipitation; in rhizosphere soil, the T-RFs responded to precipitation variation were 380 bp, 455 bp, and 487 bp, and the response mode was more complicated than that in surface soil layers. The results of CCA showed that the fungal community composition was significantly affected by soil pH, organic carbon, total nitrogen, and organic phosphorus.