Background Coronavirus disease MESHD 2019 (COVID-19) is an emerging infection MESHD disease MESHD that rapidly spreads worldwide. Clinical features and outcomes of severe COVID-19 patients with influenza virus IgM positive during the influenza season need to be described.Methods Retrospective cohort study of 140 patients with severe COVID-19 hospitalized in designated wards of Sino-French New City Branch of Tongji Hospital between Feb 8th and March 15th in Wuhan, Hubei province, China. The demographic, clinical feature, laboratory, treatment and outcome were collected and analyzed.Results Of 140 severe COVID-19 hospitalized patients, 73 patients were with median age TRANS of 66 years old with identification of influenza virus IgM-positive and 67 patients were with median age TRANS of 62 years old in influenza virus IgM-negative group. Nearly half of severe COVID-19 patients in this research are male TRANS. Majority of the severe COVID-19 patients had chronic underlying conditions. Wheeze HP was the clinical feature of severe COVID-19 patients with influenza IgM-positive (26.4% vs 9.0%, P = 0.008). On contrary, fatigue MESHD fatigue HP or myalgia MESHD myalgia HP was the feature of the COVID-19 patients without IgM-positive (38.4% vs 58.2%, P = 0.019). In laboratory examination, increased levels of ferritin and prolonging APTT were showed in severe COVID-19 patients without influenza IgM-positive compared with patients in the other group with significant differences. Death MESHD rate in the group of severe COVID-19 patients with influenza IgM-positive is higher than it is in other group with significant differences (14.9% vs 4.1%, P = 0.040). In univariate regression analysis, several factors were associated with higher risk of death MESHD, which included LDH, troponin, NT-proBNP, D-dimer, PT, APTT, lymphocytes, platelet and eGFR. However, influenza virus IgM positive was associated with lower risk of death MESHD. Multivariate Regression analysis showed that troponin and lymphocyte were independently associated with higher risk of death MESHD.Conclusion The characteristics of patients hospitalized with severe COVID-19 with identification of influenza virus IgM-positive were described. It hints proof of seasonal influenza which may overlap with COVID-19 and may cause a crisis we could confront in the future.