The production exergy cost is one of main factors of influcing the running economics for CCHP system based on microgas turbine. Different ways of making the price can cause to different product exengy cost results.Based on the conjunction matrix for CCHP exergy flow，the product exergy cost for different running conditioning are calculated in detail by using traditional and energy grades analyzing ways. The calculated results is showed that the way of ascertain the exergy cost in accordance with the energy grades is better than the traditional ways.