Abstract: Objective To retrospectively analyze the correlation between inflammatory markers in complete blood counts （CBC) and influenza A virus infection in patients visited the outpatient department of Nanjing First Hospital. Methods The suspected influenza A virus infection patients visited the outpatient department of Nanjing First Hospital from February to March 2023 were collected and divided into the positiveand negative groups based on the detectionresults of influenza Avirusantigen.Thedifferences in inflammatory markers in CBC between the two groupswere compared.The Logistic regression analysis wasused to evaluate the correlation between inflammatory markers and influenza A virus infection. Meanwhile,the restricted cubic spline (RCS) and age subgroup（<6 years,7-12 years,13-17 years, and >18 years) analysis were also performed. ResultsA total of 1487 outpatients were included, of which 404(27.2%）were positive for influenza A virus antigen. The Logistic regression analysis showed that white blood cell count(WBC)，lymphocyte percentage (LY%），and lymphocyte count (LYM) were significantly negatively correlated with influenza A virus infection (P