Human adenovirus (HAdV) is one of the most important pathogens in infants and young children with acute respiratory infections and other diseases. This article reviews the literature on HAdV, including its molecular biological characteristics, detection and typing, and pathogenic mechanism, the clinical features and epidemiological characteristics of HAdV-related diseases, and the prevention and control of HAdV infections. So far, 67 types of HAdV have been identified, including recombinant variants discovered in recent years. The major epidemic strains that cause acute respiratory infections are HAdV-3 and HAdV-7, both of which belong to the subgroup B. HAdV often leads to acute respiratory infections, but it also causes diseases of other systems. HAdV-related diseases have similar clinical manifestations as those caused by other respiratory viruses, but often accompanied by gastrointestinal symptoms. The pathogenic mechanism of HAdV remains unclear, especially for the new recombinant variants, due to few studies on their association with diseases. Because there are no prospective, large randomized controlled trials of HAdV infections, the treatment of HAdV infections is controversial. Vaccine is the most effective measure to reduce respiratory HAdV infections, but it is still not commercially available.