Great Islamic philosopher Alfarabi has put forward remarkable views on philosophical thought from logic to philosophy, from physics to metaphysics. His contributions to the field of logic have always had a great impact. Fârâbî because of his studies about logic was called “al-mu‘allim al-thânî” in the sense of “second teacher” after Aristotle, who was the “first teacher”. Because Alfarabi established logic science into the Arabic language. He did this by finding the Arabic equivalents of Greek logic terms. This is not a simple translation activity; but re-conceptualization of logic in Arabic language. In that respect, establishing a science in another language means reestablishing that science in itself. Alfarabi successfully applied this conceptualization process for every subject of logic as a whole. Logic, the instrument and method of correct thinking, is a systematic science. Logic is based on the Organon corpus attributed to Aristotle. The Organon corpus one of which belongs to someone else, consists of nine books. The contents of those books also constitute the main topics of logic. That corpus has been accepted by all those who deal with classical logic except for some minor naming and order differences. Alfarabi is also based on Organon corpus in logic. In that books, the certain of definitive proof is examined. Accordingly, a structure is built starting from concepts. It can be reached from concepts to propositions, from propositions to inferences. In that system, the concepts form the smallest building blocks of the building. In this sense, concepts are very important in logic. The concepts that have the greatest function are the five universal concepts. In this study we will try to show how Alfarabi, treats the five universal concepts in logic. Keywords: Logic, Aristotle, Alfarabi, Eisagoge, Five Universal.