The SARS coronavirus belongs to the family Coronaviridae and is an enveloped, single-stranded positive-sense RNA virus. Its structure primarily consists of spike proteins, membrane proteins, envelope proteins, and nucleocapsid proteins. Within host cells, SARS-CoV mainly localizes near the endoplasmic reticulum and Golgi apparatus, where it replicates and assembles using intracellular membrane structures. The virus participates in various biological responses, including the activation of cell signaling pathways such as the interferon response pathway, facilitating virus replication and evasion of the host immune system. SARS-CoV exhibits high genetic variability, particularly in the spike protein, especially in the receptor-binding domain, which affects the virus's host range and transmission capability.