Abstract: OBJECTIVE To investigate the molecular epidemiological characteristics and serotypes of human adenovirus (HADV) in the children with acute respiratory tract infections (ARTI) in Ningbo so as to provide bases for prevention and control of HADV infection. METHODS A total of 3023 children with ARTI who were treated in Affiliated Women's and Children's Hospital of Ningbo University from May 2023 to Apr. 2024 were recruited as the research subjects. The HADV was detected through fluorescent PCR-capillary electrophoresis, Sanger sequence typing was carried out for positive specimens, and the clinical information of the children was analyzed. RESULTS The total positive rate of HADV was 3.70%(112/3023), the positive rate was 3.34% for the male, 4.26% for the female (P=0.193);the positive rate of the 1 to 3 -year-old group was highest (5.21%),followed by the 3 to 6-year-old group (5.15%), and the positive rate of the 0 to 1-year-old group was lowest (0.81%)(P＜0.001). The positive rate was highest in summer (5.66%),followed by that in autumn (2.71%)(P＜0.001). Totally 12 serotypes were detected, with the constituent ratios, from high to low, successively as follows: type 3 for 44.64%(50/112), type 2 for 22.32%(25/112), type 1 for 10.71%(12/112), type 7 for 8.93%(10/112), type 5 for 7.14%(8/112); other serotypes (type 6, 14, 21, 34, 41, 55 and 57) were respectively detected in only 1 case. The type 1, 2, 3, 5 and 7 were most prevalent in summer and autumn, while the type 2 was most prevalent in winter. The hospitalization rate of the children with subgenus B was higher than that of the children with subgenus C after the correction with Bonferroni (P=0.007). CONCLUSIONS The preschool children with 1 to 6 years of age are dominant among the children with ARTI of HADV in Ningbo, and the summer is the peak of prevalence. The type 3 and type 2 are the predominant serotypes. The children with subgenus B have more heavier clinical burden, of whom the monitoring should be attached great importance to.