Interest in unmanned systems has been steadily increasing since the study of unmanned systems began. In particular, continuous researches are being carried out to enable UAVs and unmanned robots to be used for various missions for commercial or military purposes. As the size and complexity of mission scenarios that can be applied to these applications are increasing, research on distributed task allocation algorithm, which is a key technology for utilizing multiple unmanned mobile vehicles, is also come into the spotlight. In this thesis, we consider the communication issues in the decentralized task allocation algorithm from the viewpoint of the algorithm side. The existing decentralized task allocation algorithm is analyzed and a modified task allocation algorithm is proposed by considering communication problems. Numerical simulations of the proposed algorithm are presented and the characteristics of the proposed algorithm are discussed, as well.