Application requirements for a robust network, scalability, low cost and easy distribution are perfectly fulfilled by Wireless Sensors Networks (WSNs). They are widely used in environmental monitoring, where gathering information and forwarding it efficiently is very important. In this paper, the problem of energy management in WSN is studied, by using a proposed modified LEACH algorithm that provides improvement on energy consumption and loss rate. All these benefits is achieved by making cluster heads static and by using different level of initial energy.