The free diagnosis and treatment of clinical trial is the key problem of the quality management of the clinical trial， the free diagnosis and treatment information system of clinical trial based on the hospital information system（HIS） was constructed by the Drum Tower clinical medical school of Nanjing Medical University. In December 2016， the investigators， the researchers from assistant department and the management personnel of the clinical trial participated in the investigation by the designed questionnaire. The investigation showed that most of the researchers believe that the clinical trial diagnosis and treatment information system is simple and convenient to operate， and it greatly optimized the subject’s examination， diagnosis and treatment process. It also improved the working efficiency of the researchers， and ensured the integrity and accessibility of the clinical trial data link. Through the implementation of the system， the real?time grasping of the whole process dynamic supervision and test data of free diagnosis and treatment of clinical trial is realized， and the quality management level of the clinical trial is improved， and the clinical trial free diagnosis and treatment information system is worthy of further popularization and application in the future.