Sources of the funds of the Islamic bank are the first starting point towards forming an investing policy of the bank. Therefore, these resources should be studied well so that we can decide the favorability extent of these resources to the different forms of investment. Thus, this research will touch upon the basic sources of funds in the Islamic banks. They are of two kinds: firstly, internal sources which are the rights of the ownership of the bank that include the capital, reserves and retained earnings. Secondly, external ones which are the deposits in the Islamic banks. They are one of the most important resources of the bank ever. They also are considered the main resource that the Islamic bank depends on in most of the investiment operation. Then, the researcher moved to speak about the means of investing funds in the Islamic banks which are represented in establishing direct projects, establishing projects in conjunction with others, financing through partnership, financing through Muraabahah (i.e., selling an object while informing the purchaser of its original price and the profit he is getting in this deal), direct trading, sale of Salam (buying in advance), Mudaarabah (i.e., agreement in which a person gives an amount of money to another person in order to trade with it and the second takes a share in the profit, like a half or a third and the like), sale of Ta jeeri (leasehold) and installment sale. Then, the objectives of investing funds in the Islamic banks have been pointed out. These objectives can be divided into two groups. Fisrtly, the group of the objectives of achieving the self benefit of the Islamic bank which are represented in the objective of profitiability, the objective of safety and the objective of grwoth. Secondly, the group of the objectives of achieving the social benefit such as participating in the plans of development, providing the basic needs of socity and achieving the social solidarity.