This paper uses a qualitative description method, trying to describe the general purpose of muamalah that is to achieve many kemashlahatan and minimize kemudharatan, using principles of monotheism, khilafah, justice. On the basis of every muamalah is allowed unless there is a proposition that forbid it.The results showed that there are two principles or principles in muamalah namely general principles and special principles. In the general principle there are four main things, namely; 1) every muamalah is essentially a mubah unless there is a proposition that forbids it; 2) to bring benefit and to reject kemudharatan; 3) the balance between the transcendent and the immanent; 4) justice to the exclusion of injustice. In the meantime the special principle has two derivatives of which are commanded and which are forbidden. As for what is ordered there are three principles, namely; 1) the transaction object must be lawful; 2) the existence of kerihdaan all related parties; 3) safe and honest asset management. While the prohibited there are several principles as well: 1) usury 2) Gharar; 3) tadlis; 4) commit with people who are not lawful like crazy, child, forced, and so forth.