Abstract:【Objective】Viruses exist almost everywhere on Earth. They can infect humans, animals, plants, fungi, and even bacteria, and thus play critical roles in the biogeochemical cycling of elements and energy. Knowledge of the viruses’ community patterns and genomic information is key for proper understanding of their crucial ecological functions. This study aims to quantify the viral community patterns and functions in a farmland black soil of Northeast China and analyze their potential roles in soil ecosystems. 【Method】The metagenome sequences of the viruses were obtained based on metagenomics sequencing technology and were analyzed individually for functional gene analysis, host prediction, and genome assembly of viral Contigs. A bioinformatics software was employed to analyze the diversity patterns of the viruses. 【Result】The results showed that the majority of the viruses in the farmland black soil belonged to Caudovirales(59.38%)and Herpesvirales(2.56%)orders. This consisted of 29 families, with Siphoviridae and Microviridae representing the top two abundant families and accounting for about 44.48% and 20.53%, respectively. Gene annotation analysis revealed that soil viruses may actively contribute to numerous biogeochemical cycling processes, including nitrogen compounds metabolism, catabolism, biosynthesis, methylation, multi-organism metabolism, cellular metabolism, primary metabolism, nucleobase-containing small molecules metabolism, and organic substance metabolism, etc. Additional analysis showed that the virus hosts could be classified into 35 genera that belong to 5 phyla. 【Conclusion】With these quantitative measurements, this study provides necessary information towards advancing the virus gene database of the black soil and its ecological functions.