A method for transmitting a character message using voice recognition in a portable terminal, includes the steps of: a) displaying a guidance message associated with a voice/character conversion service when the message is created; b) connecting the portable terminal to a base station when the voice/character conversion service is selected; c) transmitting a voice message from a user to the base station; d) storing the voice message in the base station; e) allowing the base station to convert the voice message into a character message; f) transmitting the character message to the portable terminal; g) inputting a destination number; and h) transmitting the character message to a destination terminal corresponding to the inputted destination number.