The significance of this work is that ambient PM2.5 is a direct transmission mode for influenza virus infection to the human alveolar epithelium. The concentration of PM2.5 was 11.7 ± 5.5 μg/m3 in Taipei during 24 December 2019-13 January 2020. Approximately 79% of inhaled PM2.5 is able to reach the upper-to-lower airway, and 47% of PM2.5 is able to reach the alveolar epithelium for influenza virus infection. Influenza A and B viruses were detected in PM2.5 on 9 days, and the influenza A/H5 virus was detected on 15 days during the study period. FL and Pyr were negatively correlated with the influenza A virus. D(ah)P and Acp were positively correlated with the influenza B and A/H5 viruses, respectively. Cd, V, and Zn were positively correlated with the influenza A, B, and A/H5 viruses, respectively. Next, influenza A, B, and A/H5 viral plasmids interacted with carbon black, H2O2, DEPs, and UD. We observed that H2O2 significantly decreased levels of complementary DNA of the three influenza viruses. DEPs and UD significantly decreased influenza A and A/H5 viral levels. In conclusion, chemicals in PM2.5 may play vital roles in terms of viable influenza virus in the atmosphere.