A cycle model of a gas turbine power plant with effect intercooler along with a detailed parametric study is presented in this paper. The effects of parameter (design and operation condition) on the power output, compression work, specific fuel consumption and thermal efficiency are evaluated. In this study, the implementation of intercooling increases the power generating efficiency of the suggested gas turbine power plant when compared to the non-intercooled gas turbine power plant, configurations. Intercooler gas turbine cycle is analyzed and a new approach for improvement of their thermodynamic performances based on first law of thermodynamics is presented. Different effected parameters are simulated, including different compressor pressure ratios, different ambient temperature, air fuel ratio, turbine inlet temperature, and cycle peak temperature ratio were analyzed. The obtained results are presented and analyzed. Further increasing the cycle peak temperature ratio and total pressure ratio can still improve the performance of the intercooled gas turbine cycle.