Influenza A virus is a more common cause of pneumonia than influenza B virus. Influenza virus pneumonia complicated with acute respiratory distress syndrome (ARDS) is rare and has a high mortality rate. In addition to pneumonia, influenza occasionally causes neurologic, cardiac, renal, or muscular complications. Hepatic involvement in influenza virus infection has been rarely reported. We reported the case of a 7-year-old girl who was initially treated for upper respiratory tract infection, but she was transferred to the pediatric intensive care unit for intubation and ventilation after her condition deteriorated to lobar pneumonia with ARDS and liver function impairment within 7 days. Influenza B virus infection was confirmed by virus culture and serological study. Respiratory viruses, such as respiratory syncytial virus, adenovirus, influenza virus, and parainfluenza virus, are common causes of pneumonia in children; moreover, they should be considered especially in the presence of persistent leukopenia, low CRP value, lack of growth of bacterial cultures, and poor response to antimicrobial therapy. We should describe its course, diagnosis, and treatments in detail; furthermore, we reported this case to emphasize that influenza B virus may cause transient liver dysfunction and it is an etiology of pneumonia as well as ARDS.