Methods of printing an image and photo-printing systems using the methods are provided. The methods involve receiving the image from a data storage device and printing the image via a printer, the method including the operations of determining whether a Paper Full printing option in which no space is left on a printing material is selected; when the Paper Full printing option is selected, comparing a ratio of an image to be printed with a ratio of a currently set printing material; and when the ratios of the image and the printing material are different from each other, displaying a print area of the image to be printed on a display panel.The methods of printing the image and photo-printing systems using the methods provide users with an opportunity to check and re-set a print area prior to printing the image, thereby preventing an important part of the image from being cropped due to mismatch between ratios of the image to be printed and the printing material.