Objective: To analyze the hospitalization expenses of inpatients with Single?Disease based on DRGs ,and to provide statistical references for medical insurance reforms. Methods: A total of 42217 medical records from 2009 to 2013 were extracted and analyzed with nonparameter test. The decision tree model were used for DRGs ,the standard expenses and ultra line expenses were calculated. Results: The variables such as whether or not the operation, whether admitted for the first time, whether under medical insurance were included in the group rules and classified the inpatients into seven different groups.?The results show that the standard expenses calculated reached 77.87% of the actual expenses,10.76% of the cases outside the lines have consumed 32.31% of the medical resources. Conclusion: It is suggested to develop more reasonable standard?and gradually establish payment on DRGs for controlling medical expenses.