In order to find an efficient adaptive algorithm，a new Mixed Variable Step Size ELMS algorithm(MVSS-ELMS) based on Extended Least Mean Square(ELMS) algorithm is proposed in this paper. This new algorithm combines the mean square error and the correlation of the error to modify the step size. The new algorithm has been improved in anti-noise capacity and effectiveness for it fitting the principal of adjusting step-size；meanwhile，it has the superiority in convergence rate and steady-state compared to Least Mean Square(LMS) and ELMS. Computer simulations indicate that the performance of the new algorithm is better than that of LMS and ELMS on Adaptive Noise Cancellation(ANC).