Abstract: By analysing the actual room acoustic environment, this paper presents a novel algorithm for acoustic echo cancellation, which can dynamically change the coefficients update-rate of the adaptive filter. This algorithm builds up a nonlinear function relationship between update-rate and the error signal. The update-rate of the coefficients increases automatically when the environment varies, while it would be smaller in a stable state, which can lead to significant reduction in the computational burden. Theoretical analysis and computer simulations indicate that the convergence and tracking properties of this algorithm are as good as the traditional algorithms.