Abstract: Disclosed are a print region editing device and a method thereof. When an image is released during enlargement, reduction, or movement within a preset guideline portion, a print region rectangle or print region square of a longer-side length and a shorter-side length is configured according to a long-short ratio of the guide line portion and a long-short ratio of the corresponding image, and the corresponding image is enlarged or maintained so that four vertices of the corresponding image match four vertices of the configured print region rectangle or print region square, thereby freely changing a paper-full format and an image-full format depending on the enlargement or reduction of the image.