The fuel for gas turbine is normally natural gas or heavy oil, which used in the IGCC(integration generation combined cycle) is syngas with main compositions of H2 and CO. The variations of composition and heating value of fuel will lead to the requirement of some modifications for gas turbine, and the reset of operating condition points. In the paper, the characteristics of gas turbine for firing syngas are firstly analyzed, and then some measures to improve the performance of gas turbine introduced.