Abstract: A method using time-frequency analysis and dummy frequency agility to suppress ionospheric clutter based on ionospheric clutter characteristics in high frequency ground wave radar(HFGWR) is proposed.Making use of eigen decomposition cooperating in the element-pulse domain and in the element-doppler domain to suppress ionospheric clutter by analyzing the time-frequency images where the swept pulse section and the Doppler section were exactly determined in the method.Then,the ionospheric clutter suppressed by the method of adaptive sidelobe cancellation using the structural features of the array.The experimental results show that the method can effectively suppress ionospheric clutter using the data recorded of the radar.