Recently few countries have tested the scramjet engine for aerospace application. The challenge was to achieve complete combustion atsupersonic flow and to generate the required thrust for given inlet flow conditions. Research is still going on so as to attain the necessary mixing andefficient combustion inside a scramjet combustor. Performance parameter like total pressure loss across the scramjet combustor is one of the crucialparameters and has to be minimized. Factors such as equivalence ratio, inlet flow conditions affect the combustion process and hence the useful thrust.Also, the fuel injection configuration plays a vital role in mixing and thus on the performance of a scramjet combustor. Over the recent years numericalsimulation has been acknowledged as a promising tool for investigation of Scramjet flow. In this work, the investigation of effect of injector configuration hasbeen carried out using a commercial CFD tool. Validation of initial numerical results is done with existing experimental results in the available literature.Modified configurations were obtained by varying number of injection holes for same equivalence ratio. These cases were simulated to observe the rightbargain between combustion efficiency and total pressure loss. Conclusions are based on performance parameters like total pressure loss, combustionefficiency, top wall static pressure etc. Mass fraction contour plots of species are obtained to comment further on mixing and combustion performance.