The quasi-wavelet method is used for obtaining the numerical solution of the MKdV equation- The quasi-wavelet discrete scheme is adopted to make the spatial derivatives discrete, while the fourth-order Runge-Kutta method is adopted to make the temporal derivative discrete- One of the MKdV equation ut+6u2ux+uxxx=0, which has an analytical solution, is solved numerically- The numerical results are well consistent with the analytical solutions, even at t=10000s-