Current islamic banking in Indonesia is experiencing a significant growth. Up to February, 2013 the number of Islamic banks is as much as 35 banks which consist of 11 islamic banks and 24 islamic business units. This indicates that public interest in islamic banks is quite large and is projected in coming years will continue to increase along with the increasing moslems’ awareness of and need for usury-free banks. In islamic banking activities, any product will not be released from its contract. This study aims to determine the concept of contract in islamic law, principles used in islamic banking operations as well as the implementation of the murabaha contract in Islamic banking.