Stereo image processing technique has been applied to measure a three dimensional shape of corroded surface. Stereo photographs were taken at the front of view and the inclined view of a sample. The three dimensional height was calculated from the difference in position of an image between two photographs and the inclination angle. A newly developed algorithm was applied for correcting a distortion of inclined image. Mutual correlation coefficient methed was applied to calculate the corresponding points. The depth precision of this method is about 0.1mm, when photographic amplification is 2 and resolution of image scanner is 400dpi. Results from this method agree with the data measured by point micrometers. This method doesn't require any special measuring tools but a camera, and can be used as non-destructive and non-contact tests.