The present work is an attempt to investigate the advanced exergy analysis of cogeneration power plant based on gas turbine and ORC. For this propose, the ORC with internal heat exchanger and R123 as working fluid, is coupled to GT cycle by means of Heat Recovery Steam Generator. Comparing between the results of cogeneration based on GT and cogeneration based on GT-ORC, the magnitude of net power is increased from 30MW to 30.73 MW. Also, the maximum endogenous exergy destruction in the GT-ORC based cogeneration system is occurred in the combustion chamber, HRSG and GT, respectively. The HRSG is the next component to be improved after combustion chamber from the conventional exergy analysis, while the air preheater is the next component to be improved from the advanced exergy analysis.