Susceptibility effect in NMR imaging usually appears spin``s phase variation within a voxel. The phase variation affects voxel``s intensity and it is one of the causes of susceptibility effect. Since the phase variation is related with the strength of susceptibility effect, spectral analysis of the voxel can manipulate the susceptibility of the voxel. In this thesis, susceptibility effect imaging using spectral decomposition is proposed. This technique is applied to the blood imaging using susceptibility effect. As is known, the blood containing deoxyhemoglobin causes susceptibility effect and therefore a kind of angiogram is obtained using spectral decomposition. Theoretical description and computer simulation of susceptibility imaging using spectral decomposition are described. Experimental results obtained using both a phantom and a human volunteer with a 2.0 T KAIS MRI system are also presented.