ABSTRACT
SARS-CoV-2 is an RNA virus, and has a high mutation rate. The outbreak of coronavirus disease 2019 (COVID-19) began in Wuhan, Hubei Province, China in December 2019. Since then, a certain number of mutations have occurred in the SARS -CoV -2 genorne. These mutations can be classified by phylogenetic analyses to help find the infection source. However, the overall mutation rate is low, and the structure of a phylogenetic tree constructed by a single algorithm is not sufficiently reliable. To improve the reliability of classification, Paup, MrBayes, and MEGA were used to construct phylogenetic trees by different: lgorithms to analyze the genomes of all SARS-CoV-2 viruses in GenBank. In all phylogenetic trees, some sequences were clustered together in a similar pattern that coincided with the intersection of virus hosts. By comparing and analyzing similar structures between multiple phylogenetic trees, some information about the infection source was revealed. As SARS-CoV-2 evolves and genomic databases become enriched, the method of screening will provide increasingly useful information about infection sources and pathways.