In this study, three different gas turbine cogeneration systems that are preheating air, preheating air-fuel and simple cycles where steam injected in to combustion chamber are analyzed. The effects of steam injection on thermoeconomic performance are calculated and obtained. By using the first law of thermodynamics, the exergy analysis and economic methods, simulation programs written by the authors in FORTRAN code are obtained to use for the analyses. Thermoeconomic performance of these three different cycles for different stage and variable mass of injected steam are obtained and compared with literature. The effects of injection steam in to combustion chambers of those three cycles for variable compressing ratios, on power, efficiencies, product price and performances are obtained. Consequently, the advantages and the disadvantages of injection steam are evaluated. The results obtained in this study are compared with the results available in the literature. Injection steam into combustion chamber increases the electricity efficiency and electricity power but decreases the heat power of the cycles. Also the produced electricity price for per kWh is increasing.