We have established the automated processing algorithm that deals with the images of protein 2-dimensional poly-acrylamide gel electrophoresis (2D-PAGE) which is thought to be a key technology in “proteome” analysis. Our processing algorithm automatically extracts the locations and intensities of the protein spots separated and visualized in 2D-PAGE, then automatically compares it with the huge number of such images. We have also developed a WWW (World Wide Web) based 2D-PAGE image processing system “PiKA2”, that realizes automated 2D-PAGE image submission, automated spot detection and automated spot pattern comparison via a computer network with a WWW browser.