The radar cross section(RCS) of reed and zizania in the frequency range of 2?17 GHz were measured in the anechoic chamber of the microwave characteristic measurement and simulation imaging platform. The scattering and polarization characteristics of reed and zizania under continuous frequency were analyzed, and the optimal mode of measuring reed and zizania was discussed. The results showed that all polarization RCS values of reed and zizania were the largest in Ku band, followed by X-band and C-band, and the RCS in copolarization is much larger than the RCS in the cross polarization especially in low frequency when the incident angle is 35°. The RCS difference between HH and VV polarization of reed in high frequency while zizania in total frequency is obviously when the incidence angle is 55°. Through the comparative analysis of the RCS characteristics of reed and zizania, we found that reed and zizania can be basically distinguished by VV polarization and VH polarization at 7.8?17 GHz when the incident angle is 25°. And they also can be easily identified through HH polarization and VV polarization at 7?17 GHz when the incident angle is 55°. This study enriches the scattering spectral library of wetland features, and has an important significance for the follow-up monitoring of reed and zizania.