An MRI apparatus includes: a receive coil assembly including channels, and configured to receive an MR signal from an object; a data generator configured to generate undersampled image data on a k-space based on the MR signal; and a reconstructed image generator configured to generate a first reconstructed image from the undersampled image data using a parallel imaging method, and a second reconstructed image from the undersampled image data using compressed sensing. According to the MRI apparatus, since image reconstruction is performed using random undersampled image data, a parallel imaging method, and compressed sensing, it is possible to increase a speed of image acquisition and, at the same time, to improve the quality of images.