1. A printing system creating and printing a character practice worksheet for handwriting practice, comprising: a printing device; and a server connectable to the printing device, wherein the server includes a storage unit storing data of sample characters, wherein the printing device includes an image reading unit reading an image of an original document, a printing unit forming an image to print the image on paper, a handwritten character data extraction unit extracting a handwritten character, by means of optical character recognition (OCR), from the image of the original document read by the image reading unit, a sample character data retrieval unit retrieving data of a sample character that matches the handwritten character extracted by the handwritten character data extraction unit, a determination unit determining whether the matching ratio between the handwritten character extracted by the handwritten character data extraction unit and the sample character retrieved by the sample character data retrieval unit is equal to a first ratio or lower, a character practice worksheet creating unit, if the determination unit determines that the matching ratio is equal to the first ratio or lower, creating a character practice worksheet containing the sample character that matches the handwritten character and a blank cell for handwriting practice formed next to the sample character, and a print control unit controlling the printing unit to print the character practice worksheet created by the character practice worksheet creating unit on paper.