The track association of radar and Electronic Support Measure (ESM) at different sites is researched.The traditional algorithms based on statistics make decision of association for each track by hypothesis testing without making full use of the spatial distribution information of multiple targets.In this paper,the range and space distribution information is utilized for obtaining all the crossing points,which are divided into several combinations.Pretreatment based on range information is used to eliminate some false combinations and raise the speed of operation.The space distribution information of multiple targets is fully utilized by gray correlation based on the similarity.The final association results can be obtained by processing of several history association results.The simulation results show that proposed algorithm can accomplish the track association of radar and ESM quickly and effectively.