Background: 1 H magnetic resonance spectroscopy (MRS) is an analytical method that enables the identification and quantification of metabolites in samples. It differs from conventional Magnetic Resonance Imaging (MRI) in that spectra provide physiological and chemical information instead of anatomy. MRS imaging allows a valuable insights into brain tumors characteristics, grads, and progression then follow up during treatments. Typically in MRS a single spectrum is acquired by averaging enough spectra over a long acquisition time. Averaging is necessary because of the complex spectral structures and relatively low concentrations of many brain metabolites, which result in a low signal-to-noise ratio (SNR) in MRS of a living brain. Objective: In this paper, acquiring and analyzing multivoxel MRS data are reviewed by calculating the areas under different peaks then compared with that obtained directly from 1H-MRS machine. 1H-MRS measurements of amounts of Choline (Cho), creatine (Cr) and Nacetylaspartate (NAA) relative to Cho, NAA and Cr in healthy brain tissue of a normal control brain tissue, and in the tissue of tumor of patient who had taken radiation therapy sessions. Results: The obtained results show a good agreement between the data obtained directly from MRS machine and that calculated from their spectra. This method is now used for to insure that these obtained spectra are calibrated with that obtained directly from MRS machine. So these may reflect the small changes in metabolites during treatment and follow up. Conclusion: The MRS data are seen to provide unique information that when combined with high-quality anatomical MR images has implications for defining tumor type and grade, directing biopsy or surgical resection, planning focal radiation or biological therapies, and understanding the mechanisms of success and failure of new treatments