The influences of the number of heat transfer units distribution, cycle pressure ratio, specific heat ratio, etc. on the performance of an irreversible regenerative closed intercooled Brayton cycle are investigated in terms of thermal efficiency, thermodynamic efficiency, dimensionless power, entropy generation number and Ecological Coefficient Of Performance (ECOP). Different performance criteria correspond to the different optimal number of heat transfer units distribution schemes, generally, the Ntu(R) fraction is the largest, followed by Ntu(H) fraction and Ntu(L) fraction, the Ntu(I) is the smallest in the optimal distribution schemes. There exist the optimal specific heat ratios, the optimal cycle pressure ratios and the optimal intercooling pressure ratios for the maximum thermal efficiency, the maximum thermodynamic efficiency and the maximum ecological coefficient of performance in some situations. In general, the optimal specific heat ratio relatively increases as the cycle pressure ratio decreases and slightly increases as the intercooling pressure ratio increases. The optimal cycle pressure ratio increases and the optimal intercooling pressure ratio slightly decreases as the specific heat ratio decreases.