OBJECTIVE To explore the clinical features of types 3 and 7 adenovirus pneumonia in children and compare the difference between two types. METHODS A total of 47 patients with adenovirus pneumonia at our hospital from January 2009 to June 2011 were reviewed. According to the serological types, they were divided into two groups: type 3 (n = 19) and type 7 (n = 28). Two groups were analyzed statistically with regards to age, gender, clinical presentation, critical scores, laboratory examinations, radiographic findings, lung function changes, complications and prognosis respectively. RESULTS For types 3 and 7 adenovirus pneumonia, the median age of onset were 1.8 and 1.1 years old respectively. The male-to-female ratio were 14:5 and 20:8 respectively. As compared with type 3, type 7 had the longer fever time ((18 ± 10) vs (11 ± 7)days, P = 0.010), the higher critical proportion (13/28 (46.4%) vs 3/19 (15.8%), P = 0.031), the longer hospital stays ((28 ± 17) vs (15 ± 6) days, P = 0.003)), the higher proportion of involved lung ≥ 3 lobes (22/28 (78.6%) vs 4/19 (21.1%), P = 0.000), the lower oxygenation index ((192 ± 85) vs (256 ± 79) mm Hg,1 mm Hg = 0.133 kPa, P = 0.011), the higher proportion of mechanical ventilation (17/28 (60.7%) vs 5/19 (26.3%), P = 0.020) and the higher proportion of multiple organ dysfunction syndrome (16/28 (57.1%) vs 5/19 (26.3%), P = 0.037). In type 7, organ dysfunction was more obvious, particularly in nervous system, blood system and enzyme changes. Three cases of type 7 had pulmonary sequela with small airway disease. CONCLUSIONS With more severe clinical manifestations, laboratory parameters and imaging data than type 3, type 7 adenovirus pneumonia in children is more likely to cause pulmonary sequela.