Wireless sensor networks typically consist of a large number of small low-cost electronic devices with limited capacities to collect information from a given range of interest. Thus, the lifetime of a network is affected, and energy consumption increases. This paper aims mainly to activate the node and reduce energy consumption in order to transmit or receive the information from the sensor nodes. The paper considers three variables, such as residual energy, distance from the sink node, node density to select as a cluster head based on a genetic algorithm.