ObjectiveTo elaborate the contents and concrete concepts of preoperative specialized examination and evaluation of colorectal cancer of the Database from Colorectal Cancer (DACCA) in the West China Hospital. MethodThe article was described in the words.ResultsThe components, stage, accuracy, preoperative comprehensive evaluation, clinical factors of initial diagnosis, misdiagnosis and mistreatment of colorectal cancer in the DACCA were defined and elaborated in the detail. The data label corresponding to each item in the database and the required structured way in the application stage of large data were also described in detail, and the corrective precautions for all classified items were described.ConclusionsThrough the detailed description of the preoperative specialized examination and evaluation of colorectal cancer of DACCA in West China Hospital, it might provide the standard and basis for the clinical application of database in the future, and provide reference for other peers who wish to build a colorectal cancer database.