Abstract: A manner of cooperative localization for master-slave multiple UUVs(unmanned underwater vehicles) is investigated. To solve the problem of acoustic communicating and measurement delay during cooperative localization,based on path prediction of master UUV,an incoordinate interval real-time update(IIRU) method without state reverse is proposed to improve the accuracy of the slave UUV localization.In order to update the relative ranging measurements in real-time,the method firstly predicts the path of the master UUV using a statistics modeling method.In addition,based on the incoordinate interval algorithm,real-time updating algorithms are designed corresponding to the different types of sensors.Simulation results prove the efficiency of the proposed method with communication delays.