This paper deals with a two-paralleled switch-mode PWM power amplifier using current pattern tracking scheme in order to generate a gradient magnetic field in the Magnetic Resonance Imaging (MRI) system. This power conversion circuit has 8-IGBTs at their inputs/outputs so as to realize further high-power density, and to reduce current switching ripple of the Gradient Coils (GCs) as well as to raise current responses. The modern optimal preview control implementation in 2 parallel bridge type PWM power amplifier can improve the quick and precise current pattern tracking control responses in accordance with the specified values for the magnetic field in GCs. It is clearly proven from a theoretical point of view that the proposed control software is to be enlarged highly the diagnostic target and improves the image quality of MRI systems.