Abstract: With the degree of nutrient deficiency changing， the rubber leaf color changes. Therefore， the Otsu algorithm improved with characteristic of RGB dispersion for rubber deficiency leaves was proposed. Firstly， the image of RGB dispersion was calculated with the RGB three-component of color image， which retained more image color space information， then calculated the color histogram of image， and which was used to improve the Otsu segmentation algorithm. Finally， the deficiency leaf images were segmented by the improved algorithm. The results and algorithm analysis showed that the improved algorithm was superior to the Otsu algorithm in the image segmentation of rubber deficiency leaves.