Abstract: In stereophonic Acoustic Echo Cancellation (AEC) systems, the strong correlation between the two stereophonic channels leads to nonuniqueness of adaptive solutions and further large filter misalignment. To solve this problem and preserve speech quality, the psychoacoustic spectral dominance effect is utilized to propose a novel hybrid decorrelation method for stereo AEC. According to spectral dominance, weak sinusoids are injected at the three lowest harmonics so as to reduce low-frequency coherence. Besides, the nonlinear transformation method is modified and applied to high-frequency decorrelation. Comparison test on several performances with traditional approaches is carried out. Results show that the proposed method can effectively improve filter misalignment together with convergence rate. Moreover, low speech distortion can be achieved simultaneously.