Abstract: Usury is one of the subjects of which destructive effects should be recognized for all societies. Usury has harmful effects on economic and commercial relations whether it is given or taken in addition to legal prohibition and causes disorder in financial relations of people in a sound society. In this regard, it is necessary to prohibit receiving or paying any usury or performing usurious transactions. For this reason, Article 595 of Islamic Punishment Law of Iran has regarded perpetrator of this crime including usurer and broker as punishable in addition to prohibition of usury in Islamic Law. Considering importance of the subject, usury was studied from the jurisprudential and legal viewpoint in this study. Study of attitude of Shiite and Sunnite jurisprudences about usury indicates that Muslims have agreed on prohibition of usury at all times and all jurists. According to the obtained results, the Holy Quran has mentioned prohibition of usury for many times with different interpretations. The Holy Quran has mentioned prohibition of usury in five stages: Prohibition of usury for the Prophet (PBUH), disapproval of usury, telling the warning story of usury by the Jews, prohibition of gross usury and finally definite and general prohibition of usury.