The 1H-Chemical shift imaging (CSI) method was developed and applied to reveal the metabolic changes in brain tumors. In the tumor, the decrease of NAA and the increase of lactate were observed by the CSI. These changes were more remarkable in the malignant tumors than in the benign tumors. The lactate was also observed in the tissue surrounding the tumors, which was supposed to be produced in the brain with hypoperfusion condition or to be leaked out from the tumor. The 1H-CSI has an advantage to demonstrate the pathophysiological changes in a wide area of the brain.