A moving picture coding/decoding method and apparatus with improved coding efficiency. A moving picture coding method includes selecting a color space from among a plurality of color spaces, selecting a prediction mode to be commonly applied to all the color components constituting the selected color space, generating first residual data corresponding to differences between a current picture and a predicted picture for each of the color components according to the selected prediction mode, generating second residual data corresponding to differences between the first residual data, and codingthe second residual data.