Metabolic changes may occur earlier and/or may help distinguish different type of tumors. We investigated the metabolic changes using CEST MRI and characterized induced metastatic breast cancer in the brain of 10 nude rats. In vivo CEST MRI were performed at 9.4T on 3 slices with 31 frequency offsets to cover the full Z-spectra. A total of 12 tumors were analyzed for CEST signal changes. Different tumor types (solid tumor vs necrosis) showed different metabolites uptakes. Tumors located within the dentate gyrus showed significant increased values compared to the tumors in brainstem, cortex and hippocampus.