9. The apparatus of claim 3 , wherein the management unit is further configured to preserve the conversational information associated with the one contact by making the conversational messages associated with the all numbers of the one contact corresponding to a same conversational identification.
9. The apparatus of claim 3 , wherein the management unit is further configured to preserve the conversational information associated with the one contact by making the conversational messages associated with the all numbers of the one contact corresponding to a same conversational identification. 10. The apparatus of claim 9 , wherein the management unit comprises: a number updating unit configured to: preserve a correspondence relationship among the conversational identification, the number and the name of the one contact of each conversational message in a time sequence, and update the preserved correspondence relationship depending on a change in the corresponding number of the one contact; a message updating unit configured to: preserve a correspondence relationship among the conversational identification, the number of the one contact, the detailed content and the time of occurrence of each conversational message, and update the preserved correspondence relationship depending on the change in the corresponding number of the one contact; a conversational entry updating unit configured to: preserve a correspondence relationship among the conversational identification of each single conversational content and the time of occurrence and the detailed content of a latest conversational message in the single conversational content, and update the preserved correspondence relationship depending on the change in the corresponding number of the one contact; and a conversational content forming unit configured to form the conversational content associated with the one contact including a conversational entry message list and a conversational message list based on the correspondence relationships preserved by the number updating unit, the message updating unit and the conversational entry updating unit respectively and the contact information stored by the storage unit.