Group targets have fixed structure,particular motion patterns,large quantity,dense spatial distribution and serious mutual occlusion.Traditional multi-target tracking algorithms may lead to wrong data association and even target loss.Three kinds of typical research ideas for group target tracking are introduced,including the centroid group tracking algorithm,the tracking algorithm based on the random finite set and the extended state tracking algorithm.Then,the research achievements at present are analyzed and summarized.Finally, based on the existing theory and the development of advanced technologies in similar research fields,the development trends of group target tracking are discussed.