The Discrete Equations Associated With Continuous 3×3 Matrix Spectral Problems

In this paper,we first,ly summarizes the method from two continuous 2×2 matrix spectral problems KdV spectral problems and AKNS spectral problems to construct dis-crete equations through the dressing chain method.Based on this procedure,we further construct the semi-discrete equations and the fully-discrete equations associated with the three continuous 3×3 matrix spectral problems.