An MR imaging apparatus using NMR phenomenon includes a main magnet, a first, a second and a third gradient field coils, a RF coil, a RF emitter, a slice-selecting gradient field pulse generator, a reading gradient field pulse generator, a phase-encoding gradient field pulse generator, a designating device and a data processor. The phase-encoding gradient field pulse generator varies strengths of phase-encoding gradient field pulses such that, when a reference spin echo signal is placed in a middle position in a spin echo group and is first in the order within the spin echo group, phase encode amounts of the spin echo signals successively increase from the reference spin echo signal according to the order within the spin echo group. The strengths of the phase-encoding gradient field pulses are varied for gradient echo signals such that integrated phase encode amounts have absolute values successively decreasing according to the order, a direction in which the absolute values of the integrated phase encode amounts change is switched alternately with extension of a period of time, and the absolute values are greater than the absolute values of the integrated phase encode amounts of a gradient echo group having a shorter period of time.