The characteristics of energy consumption of a demand-side system of cogeneration of cool, heat and power (CCHP) with a micro gas turbine were analyzed and the fuel saving rate for different running condition was evaluated. A comparative study for the systems with and without auxiliary fuel supply for the absorption chiller was also performed. Through this study, it is found that the energy consumption rate closely depends on the efficiency of the power generation. Under the special condition as the efficiency for power generation plus grid is less than 34.5% the demand-side cogeneration system may save energy and have advantages. When the efficiency increases, the advantage of the cogeneration system may die away.