Abstract: 【Objective】To study the effects of exogenous carbon and nitrogen on the structure and function of soil fungal communities in farmland in central Guizhou，which could provide theoretical basis for the maintenance of soil ecosystem health.【Method】Four treatments，blank control（CK），adding 10 g/kg glucose alone（C），adding 1 g/kg urea alone （N），adding 10 g/kg glucose and 1 g/kg urea combined（CN），were set up in a potting experiment on a typical farmland soil in central Guizhou，and oilseed rape was planted until maturity and harvesting. Soil physicochemical properties were determined and soil fungal community structure and functional taxa were analyzed using Illumina high-throughput sequencing and FUNGuild functional prediction tools.【Result】The contents of total nitrogen，alkali-hydrolyzed nitrogen and organic matter in the soil treated with C，N and CN were all higher than those in CK. Among them，the differences in the contents of total nitrogen and alkali-hydrolyzed nitrogen were significant compared with CK（P<0.05）. The results of soil fungal community Alpha diversity analysis showed that there were no significant differences in richness index，ACE index，and Chao1 index among treatments（P>0.05，the same below）. Pielou index，Shannon index and Simpson index were increased in C and N treatments and decreased in CN treatments compared to CK，but none of them were significantly different from CK. The results of principal coordinate analysis（PCoA）and multivariate analysis of variance （Adonis）showed that the differences in soil fungal community structure between treatments were extremely significant （P<0.01，the same below）. In each treated soil sample，Ascomycota（relative abundance 78.06%-85.49%），Basidiomycota（relative abundance 1.26%-2.74%）and Mucoromycota（relative abundance 1.29%-2.52%）were the dominant phyla. Ten genera，including Fusarium，Trichoderma，Metarhizium and Botrytis，were the dominant genera. The results of redundancy analysis（RDA）showed that soil total nitrogen content was the key factor influencing the structure of fungal communities，and the results of multiple regression and random forest model analysis indicated that soil organic matter content was most closely related to fungal community richness. FUNGuild predictions showed that the soil fungal communities of each treatment could be classified into 7 trophic types，and the CN treatment increased the relative abundance of symbiotic trophic fungi and decreased the relative abundance of pathological trophic and pathological-saprophytic trophic fungi；further analysis revealed that the above 7 trophic types of fungi could be classified into 22 functional taxa，and the dominance of each treatment functional taxa were greatly different in each treatment. The analysis results of the piecewise structural equation model show that Trichoderma had extremely significant direct effect on the symbiotic trophic phenotype.【Conclusion】Exogenous carbon and nitrogen additions cause changes in soil fungal community diversity and alter fungal community structure. Soil total nitrogen and organic matter content are important factors influen-cing soil fungal community structure and abundance. The combined addition of exogenous carbon and nitrogen favors the growth of symbiotic nutrient fungi while helping to reduce the relative abundance of pathological nutrient fungi in the soil.