Abstract: A method based on Bat Algorithm to deal with the data association problem for multi-target tracking is proposed. First, the multi-target data association problem is transformed into a combinational optimization problem by modeling, and then the search and update rule of the bat algorithm is improved by combing the characteristics of multi-target data association. The new version of the bat algorithm can be applied to solving multi-target data asso-ciation problems. And in this paper, the detailed process of the bat algorithm based multi-target data association method is presented. Simulation results and test data of passive sonar show that this algorithm is feasible and effec-tive.