Abstract: The present invention relates to a data backup method on a network and a system embodying such method where a mobile phone in accordance with the present invention includes a memory part which stores data to be backed up as well as programs configured to transmit and retrieve the backup data via wireless circuits; a control part configured to process a user request for a data backup operation and transmit or receive the backup data; and a wireless circuit part configured to convert the backup data processed by the control part into radio signals and transmit the same, or convert the received radio signals into data recognizable by the mobile phone, allowing a user of the mobile phone to easily backup data and retrieve the same.