Objective Through the analysis of hospital costs of 16 866 cases of patients with lung cancer in Sichuan Province, in oder to find the main influencing factors of hospital costs of patients with lung cancer, and to provide references for reducing the hospital costs of patients with lung cancer. Methods We selected information of in-patients with lung cancer in 6 hospitals in Sichuan province from January 2008 to December 2011 based on full consideration into the local economic levels geographics distribution of different regions in Sichuan province. Then we extracted baseline data, hospitalization data and costs, and then analysis on relevant influencing factors was performed using single factor analysis of variance and multiple stepwise regression analysis. Results A total of 16 918 cases are chosen, of which, 16 866 were effective for further analysis. The results of statistical analysis showed that, the cost of western medicine accounted for the most of the average of the total hospital costs (50.79%) , followed by the cost of diagnosis and treatment (40.79%). The reuslts of multiple stepwise regression analysis showed that, the top three factors influencing hospital costs most included hospital stay, operation, and regions. Conclusion Facing daily increasing costs of hospital costs of lung cancer, effectively reducing drug expenses of patients could be a breakthrough. We could ultimately reduce the hospital costs of patients with lung cancer as well as the the economic burden of patients and society, by strengthening hospital management, shortening hospital stay, and rationally regulating drug use.