This paper describes our new method of automatic interpretation of cross sectional pictures of human body. In our case, 2- dimensional image of liver is extracted from abdominal MR images. And by reconstructing 3-dimensional (3-D) images, we had volumetric estimation. Fuzzy inference was utilized in extraction processing, so that our processing system could involve logic of image interpretation. Resulting volumetric measurement of our 3- dimensional estimation was underestimation by some 11%, when compared to that of a human expert's estimation. Our processing method is valid for segmentation of soft tissue, which is hard to be processed by only conventional image processing. And this method will lead to real time 3-dimensional image processing in the future.