An apparatus and method for processing a data backup service of a mobile terminal. The apparatus and method backs-up data files stored in a mobile terminal in a backup server over a wireless Internet. The backup server is capable of backing-up resource information of the mobile terminal. The apparatus and method comprise a) checking setup backup resources during a backup setup procedure, and attempting to establish a connection to the backup server; b) analyzing category information of data to be transmitted to the backup server after connecting to the backup server, determining the number of references if the data category is equal to data including iterative information, and determining a division interval on the basis of a file size and performing data synchronization if the data category is equal to data including binary data. The apparatus and method further comprise c) separately storing the synchronization data serving as the iterative information and combining the separately-stored results when the synchronization data is determined to be iterative information, or divisionally storing the synchronization data, combining the divisionally-stored results, and transmitting the combined result when the synchronization data is determined to be divisionally-designated data; and d) terminating a backup operation of the mobile terminal when the backup server generates a response signal after the data is transmitted to the backup server.