IoT (Internet of Thing) is a wireless network in which smart objects communicate and interact with each other through internet, it also remotely control and monitor the objects within network. In IoT, data is sensed, gathered, processed and stored from real world environment. In this procedure a large amount of energy is consumed. Energy efficiency is the main concern for IoT. In this paper introduction to IoT its layered architecture, applications and various cluster based routing protocols has been introduced. The cluster based routing protocols used different schemes to make the nodes energy efficient. The major focus of this paper is on the LEACH, SEP, HEED and TEEN protocols