An apparatus and method for inputting a character on a touch keyboard in a terminal are provided. A touch screen displays a basic key set and an extended key set. The basic key set includes consonant keys and the extended key set includes character keys corresponding to characters combinable with a consonant corresponding to a consonant key input from the basic key set. The touch screen displays the extended key set, upon input of the consonant key from the basic key set and receiving at least one character from the basic key set and the extended key set.