The steady-state and transient performance simulation program for a turboprop engine(PT6A-62) was developed. Specially this program included some algorithms, such as flat-rated behaviors in performance and limit control algorithms to prevent the compressor surge and the compressor-turbine inlet limit temperature overshoot. In order to minimize analysis errors, on interpolation method in component characteristics using matching errors and specific heat and specific heat ratio, which are functions of temperatures were used. The developed steady state performance analysis program can handle various conditions such as altitude, bleed extraction, inlet temperature and pressure and part throttle, and the transient performance analysis program incorporated a general mode for transient simulation and a control mode for prevention of the compressor surge and the turbine inlet limit temperature overshoot.