The invention provides a personal information agent system, which comprises: a receiving module used for receiving data sent from a communication device by a user; a registration module used for completing the registration formalities of the user, acquiring the name of the user and allocating storage space to the user for the user to upload personal information and a contact person list; a management module used for managing the personal information of the user and the contact person list updated by the user, identifying whether the user updates the personal information or not and appointing a contact person to inform the user the updated personal information; and a transfer module used for transferring the updated personal information to an appointed contact person. The invention provides a personal information agent method. The personal information agent system and the personal information agent method can manage the information stored in the communication device.