A character printing system in an electronic data processing apparatus is provided that is adapted for printing language characters in response to numerical value coded data entered through numeral keys of a keyboard, each character being represented by a respective numerical value coded data of a predetermined convention, wherein said language characters comprises at least two kinds of language characters, such as upper case type alphabet characters and lower case type alphabet characters, or English alphabet characters and Japanese kana characters, or the like, and the keyboard includes language character code entry mode key and language character kind specifying key as well as numeral keys and ordinary commanding keys, and a printer operable responsive to a storage for storing information entered through said keyboard is controlled by a print control responsive to said storage, whereby said printer is controlled to selectively print numerical value coded data in a kind of language characters specified by the information entered through language character kind specifying key. Since at least two kinds of language characters can be selected through mere entry operation by means of the language character kind specifying key, an increased number of language characters can be identified with numerical value coded data of a less number of digits.