Abstract: The traditional space-time adaptive processing (STAP) suppresses narrowband reverberation by utilizing the distinguishable characteristics of narrowband reverberation and target echo in space-time plane. In the paper the distribution characteristics of wideband reverberation and target echo in space-time plane are studied. Based on this, the theoretical formula is derived to analyze the influence of bandwidth on reverberation and target echo's distinguishable characteristics. It shows that the performance of traditional STAP is degraded seriously due to the overlap of wideband reverberation and target echo in space-time plane. And then, the possibility of cancelling wideband linear frequency modulation (LFM) reverberation in space-fractional Fourier domain is analyzed by integrating the space domain and the concentration characteristic of LFM signal in fractional Fourier domain.