Based on a dual-polarization high-frequency wa ve radar system, an adaptive system using horizontal antennas for the suppressio n of the Es layer interference (ELI) is described. The data received from the ho rizontal antennas were correlated with the data received from the Vertically Pol arized Antennas (VPAs) to estimate and cancel the interference adaptively in the VPAs. Suppressing the interference after each coherent integration time interva l, about 25 dB signal-to-interference ratio is expected with the experimentall y derived data. Based on a dual-polarization high-frequency wa ve radar system, an adaptive system using horizontal antennas for the suppressio n of the Es layer interference (ELI) is described. The data received from the ho rizontal antennas were correlated with the data received from the Vertically Polied Antennas (VPAs) to estimate and cancel the interference adaptively in the VPAs. Suppressing the interference after each coherent integration time interva l, about 25 dB signal-to-interference ratio expected with the experimentall y derived data.