According to the present invention, a method for storing a phone number, which automatically compares a search keyword extracted from an address book stored in a mobile communication terminal with content of a received message and informs a user of phone number change or new phone number saving, includes (S21) extracting a search keyword for each individual address content from an address book of a mobile communication terminal; (S22) the mobile communication terminal receiving a message of a sender; (S23) searching the message content using the search keyword; (S24) in the case that the search keyword is searched from the message content, displaying 'change phone number' on the mobile communication terminal; and (S25) in the case that a user selects the 'change phone number', storing a new phone number extracted from the message content in place of a phone number of a corresponding address content.