Objective: A continuous survey on influenza was conducted in hulunbuir, China from January 2010 to may 2019to reveal the epidemiological, microbiologicaland air pollutantsassociated with laboratory-confirmedinfluenza(lci) cases.methods: Influenza-like illness (ili) and severe acute respiratory infection (sari) subjectswere enrolled fromasentinel hospital in hulunbuir during the study period forepidemiological and virologicalinvestigation. The association between air pollutantsand influenza-positivity rate was assessed by generalized additive model (gam).results: Of 4,667 specimens, 550 (11.8%) were tested positive for influenza.the influenza-positivity was highest in the age groups of 5-14 years, 50-69 years and ≥70 years. We found that the effect of particulate matter≤2.5 μm (pm2.5)concentrations on influenza-positivity rate was statistically significant, particularly on day lag-4 and lag-5. Genetic characterizations showed that (h1n1) pdm09 strains belonged to subclade 6b.1 and that influenza b isolates belonged to subclade 1a-3del,with significant substitutions in the ha(hemagglutinin)and na(neuraminidase)proteinscompared with those in the who-recommended vaccine strains.conclusions:elderly individuals and school-age children were at high risk for influenza infection. Pm2.5concentrations showed significant effects on influenza-positivity rate in hulunbuir,which could be considered in local influenza preventionstrategies. © 2020 Cambridge University Press. All rights reserved.