Clinical studies remain the corresponding risk, during the study period can sometimes cause pa-tients/subjects health damage directly or even life safety;also some at the end of the study after a certain period or in the offspring can reflect the long-term adverse effects. Clinical research project risk classification method is dis-cussed, according to the influencing factors of risk can be divided into two categories, their sexual and artificially, and from their sexual risk, the researchers risk, the sponsor problems and subjects of the four aspects of risk identi-fication and evaluation is discussed in detail. Based on this, advances the tactics of risk aversion: construction of clinical research and regulation of ethical management platform,To strengthen the external supervision of research project risk, The sponsor or researchers do their job, To strengthen the construction of institutional ethics committee ability, Give full play to the institutional ethics committee functions,Risk transfer and reduce the risk.

Objective: To study the meal qanity of the patient with chronic renal failure(CRF). Methods: The nutritional state of 140 CRF patients was researched,basing on the diet history. Results: With the progression of course of CRF ,the nutritional states of patients with CRF were getting worse . Conclusions: The nutritional state of CRF patients should be paid attention to.

In recent years , with dramatic increase of the number of clinical studies , researchers and ethical committees face with the new challenge of ethical issues about protection of subjects .Based on the experience of previous ethical review , this article summed up a few typical cases of clinical research , involving the practical ethi-cal issues, such as the goal of research , informed consent, and compensation for damage caused by research .And then it analyzed the ethical issues in these cases , and proposed some suggestions for the reference of clinical re-searchers , ethical committees and policy makers .

Objective:To investigate the reasons of the tension of doctor-patient relationship and the medical violence from the perspective of the doctors, in order to provide a reference for finding a viable solution. Methods:Questionnaires survey were conducted about doctors' working conditions in 45 hospitals of 9 provinces. Results:On-ly 3. 6% medical staff had a harmonious doctor-patient relationship, the causes for the tense doctor-patient rela-tionship were poor communication with patients (75%), medical limitations (46. 2%);From the patients perspec-tive, the patients 'unpleasant caused by overtreatment due to complex illness accounted for 54. 2%;Institutional health-related reasons accounted for 82 . 6%. Conclusions:In the past five years after the new health care re-form, the tense doctor-patient relationship has not been released. So, should focus on training to enhance the com-munication skills of medical personnel and medical humanities education while the implementation of the national health care reform, in order to reduce iatrogenic conflicts.