With the broad application of sequencing technologies, many novel virus-like sequences have been discovered in arthropods, including mosquitoes. The two main categories of these new mosquito-associated viruses are "mosquito-borne viruses (MBVs)" and "mosquito-specific viruses (MSVs)". These novel viruses might be pathogenic to both vertebrates and mosquitoes, or they could just be symbiotic with mosquitoes. Entity viruses are essential to confirm the biological characters of these viruses. Thus, a detailed protocol has been described here for virus isolation and amplification from field-collected mosquitoes. First, the mosquito samples were prepared as supernatants of mosquito homogenates. After centrifugation twice, the supernatants were then inoculated into either mosquito cell line C6/36 or vertebrate cell line BHK-21 for virus amplification. After 7 days, the supernatants were collected as the P1 supernatants and stored at -80 °C. Next, P1 supernatants were passaged twice more in C6/36 or BHK-21 cells while the cell status was being checked daily. When cytopathogenic effect (CPE) on the cells was discovered, these supernatants were collected and used to identify viruses. This protocol serves as the foundation for future research on mosquito-associated viruses, including MBVs and MSVs.