With the influence of shadow on plant leaf images in natural environment, extraction of foliar features will be seriously affected. Hence, this paper proposes a method of shadow detection and removal based on YCbCr color space. First, the intensity of channel Y in YCbCr color space is calculated and the shadow regions are detected by a threshold on the intensity. Then according to the shadow model, light restorations for each pixel in shadow regions are made and the results are finally transformed to the RGB color space. Compared with direct shadow removal in the RGB space, this method weakens the edge effect, thus making the color between the post removal shadow region and non shadow region more uniform and the restored images more natural.