<FONT face=Verdana>In wireless sensor networks

the localization space can be divided into distinct regions such as vertice

edges and faces in traditional sequence-based algorithm. But the average location error for locations in a face region is quite in evidence. For the problem of localization error

a new algorithm which is based on the sequencebased algorithm and the three orthocentres method is proposed here. Its principle and realization method have also been studied. The new algorithm uses the three maximal values of Rank Order Correlation Coefficient to judge the three nearest centroids and computes its orthocentre to exclude areas in which nodes do not exist. The new algorithm will bring some computing increases. However

it does not need additional improvement in hardware or complexity of nodes. Simulation experiments prove that the new algorithm can obviously improve the localization accuracy compared to the traditional sequence-based algorithm and the three orthocentres method. If the proportion of anchors increases

the localization error will decrease markedly.