Within the scope of this study, a 0-dimensional code is developed by using Stream Thrust Analysis in order to evaluate scramjet cycle performance with respect to selected performance parameters (specific impulse, overall efficiency) and combustion chamber exit temperature. By using the results of this code an analysis employing "Design of Experiments" (DoE) is performed to determine the most effective input parameters and/or interactions on the scramjet performance. The results showed that most effective input parameter for all of the selected parameters is fuel/air ratio. Selected parameters are evaluated first individually then simultaneously. The purpose of evaluating the performance parameters simultaneously is to determine the input parameter set which gives the highest values of specific impulse and overall efficiency while giving the lowest value of combustion chamber exit temperature. As a result the input parameter sets for different cases are determined.