Objective: To explore reasonable methods of subdividing Adjacent DRG into DRG by introducing PCCL principle and provide appropriate DRG grouping method in line with Chinese national conditions. Methods：Clinical complexity level of each complications or comorbidities was assigned by clinicians. Patient clinical complexity level (PCCL) model was selected to calculate the clinical complexity scores of cases. Each Adjacent DRG was subdivided into DRG groups by CART model. The rank-sum test was applied to test the statistical significance of the grouping results. Results: 9 surgical Adjacent DRGs were subdivided into 18 DRG groups. There were statistical significance in the differences of hospitalization expenses and Length of stay between different DRG groups in each adjacent group. Conclusion: PCCL model showed high performance in DRG subdivision. The unification of the quality of medical records and coding is the key factor to ensure the reasonable grouping results.