In performing the moving table imaging, an MRI apparatus and a method thereof are provided, which minimizes image degradation and reduces imaging time. When an image of a wide range of a test object is taken, the imaging is repeated while changing the gradient magnetic field intensity in a phase-encode direction, as well as changing the size of field of view FOV in the readout direction by changing the readout gradient magnetic field intensity in reading out the data, according to the phase-encode amount. In a part where the FOV is expanded, data acquisition frequency is lowered, and consequently, the total imaging time is reduced. The data sampling time may be changed along with the change of the FOV, and therefore, a process for achieving a unique matrix size in the readout direction is rendered unnecessary, and a spatial resolution can be maintained.