Abstract: To solve the problem of cluster communication with the unequal power and cluster of overlapping coverage as location of the unreasonable distribution of the cluster heads in LEACH，an improved LEACH_UD algorithm is presented.In the cluster heads of the initial phase of the elections，the distance of two cluster heads considered for cluster heads uniformly distributed in the regional monitoring，and the other is to cancel the extra energy consumption by the each round of re-cluster.After the initial meeting to determine cluster，the distribution and the numbers of clusters are no longer changing and each of the next round of the cluster head is designated by the cluster head of the last round.Both LEACH_UD and LEACH are simulated in NS2.The simulation results prove that LEACH_UD algorithm is much better than LEACH algorithm in network lifetime and LBF.

Key words: cluster head uniformly distributed, clustering routing algorithm, network lifetime, Load Balance Factor（LBF）

摘要： 针对LEACH算法中，簇头位置分布不合理时导致的簇内通信能耗不均和簇的覆盖区域重叠的问题进行了改进，提出了LEACH_UD算法，一是在簇头的初次选举阶段，要考虑簇头之间的距离，使簇头大致均匀地分布在监测区域；二是取消LEACH协议中每轮重新成簇所带来的额外能量消耗，当初次簇头确定以后，簇的数量和分布不再变化，每一个簇的下一轮簇头由上一轮的簇头根据节点的能量情况来指定。用NS2对LEACH算法和LEACH_UD算法进行了仿真和比较，验证了LEACH_UD算法的有效性。

关键词: 簇头均匀分布, 分簇路由算法, 网络生存时间, 负载平衡程度