In this paper, a novel approach, which automatically measures the illumination instability of the video, is proposed to provide selection measure of target video for colorbased multimedia system. An information-theoretic measure is proposed as a quantitative measure of the information distribution within an image. This measure is further extended to the video case and used to quantitatively represent the lighting condition of each scene. The illumination instability of the video is thus measured by calculating the instability of the features extracted from the extended measure. Experiments are generated to demonstrate how the proposed approach using the information-theoretic measure to take information distribution within an image into account can reflect the instability more effectively than other simple and straight-forward measures, and how to use it to provide selection measure of target video for color-based multimedia data indexing system.