A de-interlacing method is applied to a to-be-de-interlaced field including display pixels of display lines and to-be-interpolated pixels of to-be-interpolated lines. First, a corresponding edge-direction value of each of edge pixels in the to-be-de-interlaced field is determined. Next, it is judged whether one of the display pixels near each to-be-interpolated pixel has a corresponding edge-direction value so that a judgement result is obtained. Then, a corresponding edge-direction value of each to-be-interpolated pixel is set according to the corresponding edge-direction values of specific display pixels of the display pixels near the to-be-interpolated pixel if the judgement result is affirmative. Finally, a corresponding display pixel pair of up and down display lines near each to-be-interpolated pixel is selected according to the corresponding edge-direction value of each to-be-interpolated pixel so that a luminance value and a chrominance value of the to-be-interpolated pixel are calculated.