Immoral actions in medical research in past has increased that sensitivity to this subject. A review on international laws shows that sometimes these researches has violated ethics and has examined people without to tell them about the experiments. The Nuremberg law was made for to trial Nazi's Medicines in 1947 that had been experienced people without they know about the tests. According to this law voluntary consent of experienced people is necessary. According to the Helsinki declaration (1964): medicines have to study on the people with consent of them (Angellier 2001(. In some ills clinical research on the patients produce verity moral problems. In these cases, in regard to their subject, national and international laws approve such research. In regard to above cases the main question in this paper is: how much are allowable medical research for national and international laws? First object was to review of international laws of related to this subject then we investigated national laws. Study is documentary - comparative and used resources were books and laws of related to medicine.