Abstract: This paper presents a method of applying a system which consists of an optoelec-tronic scanner (TV camera or CCD),a microscope and an IBM-PC computer to abtain the micrograph information from the worn region on the flank of the cutting part of the tool and analyze and process the picture by means of imagine processing and mode recognizing tech-nology,The on-line and off-line methods are used respectively to calculate accurately the worn value,recognize the form of wearing. Base on these,the manufacturing process could be recognized and controled. At the last,the optimum values of cutting velocity and feed are given, which meet the principle of the lowest cost and longest tool life. It is proved by experi-ments that the conclusion of the theoretical analysys and calculation agrees with the practical tests. The article provides a practical and precise way of recognizing and controling manufac-turing process on line.