A Robot vision system was designed using a silicon retina, which has been developed to mimick the parallel circuit structure of the vertebrate retina. The silicon retina used here is an analog CMOS very large-scale integrated circuit, which executes Laplacian-Gaussian like filtering on the image in real time. The processing is robust to change of illumination condition. Analog circuit modules were designed to detect the contour from the output image of the silicon retina and to binarize the output image. The images processed by the silicon retina as well as those by the analog circuit modules are received by the DOS/V-compatible mother-board with NTSC signal, which enables higher level processings using digital image processing techniques. This novel robot vision system can achieve real time and robust processings in natural illumination condition with a compact hardware and a low power consumption.