The aim of this paper is the description of the performance characteristics of a powerplant intended for modern STOVL fighters. Based on a general two-shaft gas turbine performance simulation software, a variable cycle engine performance simulation software was developed with introduction of Lift fan and Roll posts modules. The cycle operating parameters were given, such as low pressure turbine nozzle area, mode selector valve area and propelling nozzle throat area. Selected supersonic cruise as designed point of the engine, determined the combination of the parameters which forming the design point of the engine. The performance characteristics of variable cycle engine with a low pressure shaft driven lift fan were calculated and analyzed on supersonic cruise Design Point, SLS and STOVL in this paper. Comparing the parameter values of SLS and STOVL points, it is actually verified that the innovative variable cycle propulsion system offers high levels of thrust augmentation, by altering the effective engine bypass ratio, offering simultaneously improved fuel consumption.