We consider the Cauchy problem for the generalized Korteweg-de Vries-Burgers equation with initial data,where, is the Fourier multiplier associated with the symbol |£|2α. For the generalized KdV-Burgers equation, we study the well-posed and ill-posed problem with initial data in the homogeneous Sobolev Space Hs and Sobolev Space Hs, separatively.To solove the well-posedness of the equation mentioned above, the main difficulty is how to get the bilinear estimate. Here , in the Sobolev Space Hs, with s > —α, we get the bilinear estimate using dual method by dispersive relation satisfying a algebraic smoothing relation:When s > —α, in the Sobolev Space Hs , the solution of the generalized KdV-Burgers equation can be proofed to be well-posed by the bilinear estimate and the Fixed Point Theorem.In the homogeneous Sobolev Space Hs, we get the bilinear estimate by dyadic decomposition and abstract multiplier principle by T.Tao. When homogeneous Sobolev Space Hs, the solution of the generalized KdV-Burgers equation can be proofed to be well-posed also by the bilinear estimate and the Fixed Point Theorem. Correspondingly, when , the solution of this equation can be proofed to be ill-posed by dimensional analysis. |