A display method of a plasma display device and plasma display device are provided. The display method includes nonlinearly converting first image data corresponding to an input image signal to second image data having a gradation value smaller than a gradation value of first image data and expressing the second image data by a real part and an error part. The display method includes error diffusing of, when the error part of the second image data is not zero, spatially or temporally diffusing the error part. The display method includes subfield pattern converting of selecting a lighting pattern of the subfields based on the error-diffused second image data.