To explore the major factors influencing the disease burden of patients with lung cancer by the pathway analysis method. Descriptive statistical analysis and the pathway analysis method were applied and the medical records of discharged patients with the primary diagnosis of lung cancer at a tertiary hospital in Anhui province between January 2013 to December 2019 were collected to explore the factors affecting medical costs of patients with lung cancer. The results showed that the average medical cost of 25 817 patients with lung cancer with a median of 12 197.20 yuan， and the median length of stay was 8 days. The length of stay was the principal factor affecting hospitalization cost. Gender， application of new targeted anticancer drugs， surgical operation situation， age， year of discharge， condition at admission and discharge had indirect effects on hospitalization cost through length of stay. Length of stay and payment methods only affected hospitalization cost directly； however， gender only had indirect effect. Therefore， length of stay is the main factor affecting the hospitalization cost of patients with lung cancer. Shortening the average length of stay should be taken as the starting point of hospital fine management， and comprehensive measures should be taken to reasonably reduce the disease burden of patients with lung cancer.