Answer： The concept of "non therapeutic clinical trials" can be referred to in the Helsinki Declaration (1996 and earlier versions), namely "pure scientific application of medical research, the experimental design is not related to the patient's ill ness", such as phase I and bioequivalence trials with healthy volunteers as subjects. Regarding the judgment of clinical benefits, According to the 2016 edition of the CIOMS International Ethical Guidelines for Health related Research Involving Humans, guideline 4 explains: "A study intervention offers a prospect of clinical benefits when previous studies provide reliable evidence that the intervention's potential clinical benefits will exceed its risks When early clinical trials do not have sufficient reliable safety and efficacy basis, they are considered as trials without expected direct clinical benefits.