A digital video signal processing apparatus and method for field-based adaptive Y/C separation includes an adaptive 3D BPF performing Y/C separation according to local comb filtering/1D band pass filtering when the edge direction is fixed vertically/horizontally in response to spatio-temporal local characteristics of an image using spatio-temporal filters. When the edge direction is not fixed horizontally or vertically, the 3D BPF performs 2D/3D band pass filtering in all directions. The 3D BPF adaptively and continuously carries out comb filtering, 1D band pass filtering and 2D/3D band pass filtering in response to the spatio-temporal local characteristics of the image.