High-contrast imaging of magnetic domains were performed using magneto-optical Kerr effect enhanced by the plasmon filter. The plasmon filter was prepared by annealing Au thin films deposited on a SiO<sub>2 </sub>substrate. Au nanoparticles were formed by deforming the Au thin film. The filter exhibited an intense absorption peak at wavelength around 570 nm. The images were obtained setting the filter onto a magnet surface using a magneto-optical Kerr effect microscopy. The image contrast was evaluated by comparing Coefficient of Variations (CV) which exhibited the variation of the data in luminance histograms of the observed images. As the value of CV increases, the range of the luminance value expressing the image of magnetic domains is increased. The value of CV of the observation image with the plasmon filter was larger than only substrate, indicating that the contrast of the observation image was improved. High-contrast image of magnetic domains was obtained using the plasmon filter.