Throughout their history, Muslims have used various weapons during their wars before the invention of the cannon. For example, they would use special devices in a siege battle the function of which was to destroy the defensive city walls. We can identify the catapult as the most important and efficient of these instruments. During the median centuries of Islam, various types of this weapon such as ballista, trebuchet, Mangonel and Springald and Maritime; Arabi, Farangi, turki, sultani etc… aided Muslims tremendously during war and the course of its evolution went parallel to the evolution of the defensive city walls; to the extent where different types of this weapon were designed and built in the Islamic world. Up to now certain and clear divisions of the various types of catapults have not been provided. In the present paper we aim to divide the various types of catapults based in their mechanism and method of operation, type of construction, operation and projectiles and explain each one’s effect and operation.