A wireless sensor network (WSN) is an emerging field comprising of sensor nodes as basic units. These sensor nodes have limited resources like power, memory etc. WSNs can be used to monitor the remote areas where recharging or replacing the battery power of sensor nods is not possible. This limitation of WSNs makes energy consumption as a most challenging issue. Low-Energy Adaptive Clustering Hierarchy (LEACH) is an easiest and first significant protocol which consumes less amount of energy while routing the data to the base station. A lot of work has been done to improve energy efficiency of routing protocol by taking LEACH as a base protocol. In this review paper section I has introduction to Wireless Sensor Networks, section II has introduction of LEACH Protocol and all descendant protocols of LEACH with comparison table have been discussed in section III.