The cooling system plays an important role in high-efficiency energy utilization for data centers and airflow improvement is one of the most effective ways to reduce cooling system energy consumption. In this paper, the applicability of entransy analysis method is studied and compared with the exergy analysis method. The results show that the minimum entransy-dissipation-based thermal resistance for the heat transfer between the cooling air and the racks always corresponds to the optimal system parameters for the data center cooling system, but the exergy analysis method is not always effective. Therefore, the entransy-dissipation-based thermal resistance is more suitable as the object parameter to optimize the airflow organization in a data center. (C) 2014 Elsevier Ltd. All rights reserved.