1. A method for providing caller identification information by a caller's mobile phone, the method comprising the steps of: when there is a request, by a caller, for an addition of a word or phrase after an input of a call recipient's phone number, receiving, by the caller's mobile phone, an input of the word or phrase from the caller; and when the caller inputs a request for making an outgoing call, generating, by the caller's mobile phone, an outgoing call message, which includes a caller's phone number, the recipient's phone number, and an input word or phrase, and sending the generated outgoing call message to the recipient's mobile phone, wherein receiving the input of the word or phrase from the caller comprises: upon generating an identifier to request addition of the word or phrase, distinguishing the recipient's phone number and the word or phrase and adding the identifier after the recipient's phone number; and receiving the input of the word or phrase from the caller, and continuously arranging the recipient's phone number, the identifier and the word or phrase in order and displaying the recipient's phone number, the identifier and the word or phrase on a single screen of the caller's mobile phone.
2. The method according to claim 1 , wherein, in the step of receiving the input of the word or phrase from the caller, the caller's mobile phone receives the input of the recipient's phone number as a phone number directly input by the caller.