Objective To explore the clinical characteristics of influenza complicated with Mycoplasma pneumo-niae(Mp) infection in children, and provide reference for diagnosis and prevention of influenza complicated with Mp infection. Methods 328 children with fever who met the screening criteria in a hospital from January to December 2017 were studied, according to the initial diagnostic results, children were divided into influenza combined with Mp infection group (n=87), simple influenza infection group (n=149) and simple Mp infection group (n=92), blood and serum immune markers of children in three groups were compared. Results Of 328 children with fever, 87 (26.5%) were with both influenza and Mp infection, mainly in children aged 1-6 years in autumn and winter. Compared with simple influenza group, symptoms of cough, expectoration and pneumonia in incldren in influenza combined with Mp infection group were significantly higher (P<0.05). Compared with simple Mp infection group, children in influenza combined with Mp infection group had more cough and expectoration. Compared with simple influenza group and simple Mp infection group, the number of children with moderate and high fever in influenza combined with Mp infection group was significantly higher, duration of fever and length of hospital stay were longer, percentage of monocyte and neutrophil increased significantly, percentage of lymphocyte reduced significantly, and proportions of abnormal IgG, IgA, IgM, C3, and C4 positive were significantly higher. Conclusion Influenza combined with Mp infection in this region occurs frequently in autumn and winter, clinical manifestations of influenza combined with Mp infection are characterized by prolonged symptoms of moderate and high fever, symptoms of cough and expectoration are more serious than those of common influenza, and immunological test results are obviously abnormal.