Objective To analyze the characteristics of hospitalized children with asthma exacerbation, and provide clinical reference for the diagnose and treatment of asthma. Methods Clinical data of children with bronchial asthma admitted to the Respiratory Center of Children's Hospital of Chongqing Medical University from January 2011 to June 2021 were retrospectively analyzed. Results 900 children were enrolled in the study, including 615 boys and 285 girls, with a median age of 2.3 (1.3-3.9) years. In the study, 559 toddlers, 246 preschool children, and 92 school-age children were enrolled, and significant differences were found in the proportions of boys and in the time distribution of initial diagnosis as asthma among the three age groups (P<0.05). The proportion of children first diagnosed with asthma after admission was 63.5%. The percentage of children admitted for mild acute asthma attacks was 76.6%, with more infants (475 cases, 52.8%) followed by preschool children (180 cases, 20.0%). Among 900 children, 501 (55.7%) had pathogenic bacteria detected by sputum culture, with the highest proportion of Streptococcus pneumoniae (26.9%), followed by Moraxella catarrhalis and Haemophilus influenzae. The positive proportion of four viruses detected in the study, including respiratory syncytial virus, adenovirus, influenza virus, parainfluenza virus, was 25.0%, and of which respiratory syncytial virus had the highest detection rate (16.3%). The difference in the proportions of asthma children combined with allergic rhinitis or sinusitis among the three age groups was statistically significant (P < 0.01). A total of 224 children were tested for allergen sIgE, of which 119 children (53.1%) were positive for inhalant allergens and 76 children (33.9%) were positive for foodborne allergens. Dust mite (27.7%) was the most important allergens, followed by house dust (8.9%). There were significant differences in the positive rates of most inhalant allergens (e.g., dust mite, house dust, cat and dog hair, tree allergens, mulberry, etc.) between the three age groups (P < 0.05). Conclusions Mild acute asthma attacks was the most important cause for hospitalization in children under 6 years old with asthma being firstly diagnosed after admission. Respiratory tract infection was the most important trigger of acute exacerbation of asthma. For children with asthma, allergen screening and allergic rhinitis prevention and treatment should be emphasized.