We derive a modified analytical expression of a quantum radar cross section (QRCS).Subsequently,we present a comparison between the QRCS and a classical radar cross section (RCS) and analyze the factors that can affect the intensity of the peak and side lobes.Simulation results on a fiat rectangular plate demonstrate that QRCS has a similar structure to that of RCS.The analysis of side-lobe structure can benefit the design of quantum stealth platforms as well as the research on quantum radars.