Objective To analyse the structure of medical cost and its development in inpatients with non-small cell lung cancer, and to explore appropriate methods to analyse the impact of different expenses on the hospitalization expenses. Methods New grey correlation analysis was employed to quantitatively analyse 6 kinds of hospitalization expenses of 600 patients with non-small cell lung cancer in 2 municipal hospitals in Nanjing between 2005 and 2009. Results New grey correlation analysis revealed that the relational degree of 6 kinds of hospitalization expenses sort order from the highest to the lowest were medicine, treatment, operation, examination, laboratory test and bed occupation. Medicine charges and treatment costs were the main factors affecting hospitalization expenses of patients with non-small cell lung cancer, while bed charges had the lowest association with hospitalization expenses. Conclusion New grey correlation analysis can provide reliable results with simple calculation steps, which is suitable for the dynamic analysis of relational degree of different hospitalization expenses.