In an apparatus for providing a multimedia streaming service, a server transmits a Media Presentation Description (MPD) including information about media data to a client, receives a partial request message requesting a part of media data having a range according to a defined range in the MPD, and transmits to the client a segment having the range in response to the partial request message. The segment includes at least one fragment, segment index information indicating the position of the at least one fragment in the segment, and fragment index information including information indicating the position of each of a plurality of samples included in the at least one fragment and information about a total size of the samples.