The wireless sensor network is an emerging and interesting area among researchers. New technological advancement makes high processing speed and lifetime of power sources possible. In Heterogeneous wireless sensor network there are two major problems; one is difficult to manage complex heterogeneous nodes in network and second is network lifetime due to high network operations load. Network operation includes an important process; The Cluster-head selection process. This process alone consume significant amount of node energy. To achieve high network lifetime in case of heterogeneous wireless sensor network case, Cluster-head selection process should be energy efficient. Thus this Energy efficient algorithm has been proposed for cluster-head selection process. The proposed algorithm introduces the modified probabilistic function for heterogeneous nodes. Nodes are selected as Cluster-heads according to this proposed probabilistic function; have different probability for CH election of each type of heterogeneous node. This probabilistic function also includes Energy threshold for nodes. Due to all this high network life time obtained.