Disclosed are a method and device for scheduling transmission time of media data. The media data comprises a plurality of media data units. In one embodiment, the device comprises: a first determination unit configured to determine a latest time for transmitting each media data unit; a second determination unit configured to determine an earliest time for transmitting each media data unit; and a scheduling unit configured to schedule a transmission time for each media data unit by rule of: if the determined latest time for a media data unit is not less than the determined earliest time for said media data unit, the scheduling unit selects a maximal one from the determined earliest time and a predetermined transmission time for said media data unit as the transmission time, otherwise, the scheduling unit schedules the transmission time at the determined earliest time.