A character input apparatus and method in a terminal are provided, in which a touch screen displays a first key set and a second key set. The first key set includes first letter keys with all consonants and a second letter key with symbols indicating Tone Marks (Tms) and positions of predetermined vowels, for inputting all vowels and Tms. The second key set includes the predetermined vowels or Tms. Upon selection of a symbol by the second letter key, the controller controls the touch screen to display the second key set and receives at least one letter by the first key set and the second key set.