The effect of gap location heterogeneity on decomposition of plant fine roots and soil fungal community diversity was investigated in a forest with Cupressus funebris plantation for 30 years, in the hilly region in central Sichuan Province. In an area with gap size 200 m², the structure and diversity of soil fungal community associated with 2a natural decomposition of fine root of Toona sinensis were investigated separately on three different locations:gap center (GC), gap boarder (GB) and closed canopy (CC), by using Illumina MiSeq high-throughput sequencing technology. The results showed that there were significant differences in microenvironment across different gap locations (P<0.05). The response of soil physical and chemical properties to the gap position was more sensitive than that of fine root nutrient elements, and the decomposition rate of fine roots at GB position was significantly higher than that of GC and CC. There was no significant difference in soil fungal community at phylum level. Ascomycetes and Basidiomycetes were dominant groups across different gap locations. Base on FUNGuild results, the trophic modes of saprotrophs showed significant differences across different gap locations, the classes of Eurotiales, Hypocreales, Sordariales, Chaetothyriales and Agaricales were dominant with the relative abundances>1% across the three locations. The relative abundances of Agaricales and Chaetothyriales were significantly different between GB and CC (P<0.05). The genera of Penicillium, Aspergillus, Chaetomium and Staphylotrichum were the dominant taxa, and there were significant differences in their relative abundances across the three locations (P<0.01). The α diversities of the fungal communities were not significantly affected by the gap locations, but their β diversities were more responsive to different gap locations. The β diversity at GB was significantly higher than those at GC and CC (P<0.05), with the largest number of shared species at GB and the largest number of endemic species at GC site. Redundancy analysis revealed significant effects of the environmental factors on the fungal community (P<0.01). Partial Mantel test showed that the factors such as pH, water content (SWC), temperature (ST), available P (SNP) and total N (STN) in soil were important factors influencing fungal community diversity. In conclusion, forest gap locations significantly affected the composition and diversity of soil fungal community. The findings were helpful to regulate the underground ecological processes such as fine root decomposition in cypress plantation forests.