Abstract: A turboshaft aeroengine WZ5 was modified into a gas turbine working with semiwater gas.The features of its modification and its fuel gas supply system are described,testing program and results of its performance tests are discussed.It is shown that its starting reliability,burning stab ility,acceleration response,distributional quality of the exit temperature field and the operating performeance are reasonable,some of them are even better than the original WZ5 engine working with aviation kerosene.