Background: Bronchopneumonia is a disease with a high death rate for children in developing countries. It not only affects the healthy growth of children, but also puts economic pressure and additional burdens on their families and society. Social development and advancement may change the factors influencing the hospitalization costs. This study aimed to explore reasonable cost control approaches by analyzing the factors related to unreasonable increases in medical costs, so as to standardize the diagnosis and treatment behaviors and determine management methods for scientific medical costs. Methods: Using the decision tree analysis method combined with the characteristic variables of inpatients, data mining and analysis were performed on the assortment of charges for15,980infantile bronchopneumonia inpatients in a northern hospital of China during January 2013 to December 2017. Results: The medical costs of infantile bronchopneumonia inpatients tended to decrease year by year. Various factors influencing the hospitalization costs were sequenced in order of decreasing importance: salvage, complications, admission condition, discharge condition, hospital stay, age and medical payment mode. The hospitalization cost of 623(78.5%) patients with salvage during hospitalization was >RMB 10,000. Hospitalization cost of