Quality of clinical research is related closely to the study design. Referees and editors from medical journals, as an essential part of medical research community, must shoulder the responsibility to have the most reliable and scientific evidence for medical sciences published, rather than the inferior studies with incorrect study design and unreliable results. The studies should be evaluated based on its nature. In this paper, we introduced the points on evaluating the medical papers about clinical trials from several aspects, like subjects enrollment, treatment measures, observed parameters, sample size, balance between statistical and clinical significance etc. We aimed to call attention from medical paper referees, editors, as well as researchers themselves.