Robot Soccer game is become popular recent years. The system combined with mechanic

electronic

control

computer

image process and etc. In order to win the game

the system must be more quick and more accuracy. Because vision sub-system is the first step of the whole system

its speed and accuracy are important to the whole systems speed and accuracy. Real-time segmentation is the first step in the color-vision system on the robot system. A color image segmentation method using improved seed-fill algorithm in YUV color space is introduced in this paper. The new method dramatically reduces the work of calculation

and speeds up the image processing. The result of comparing it with the old method based on RGB color space was showed in the paper. The second step of the vision sub-system is identification the color block that separated by the first step. A improved seed fill algorithm is used in the paper. The implementation on MiroSot Soccer Robot System shows that the new method is fast and accurate.