An opening-closing guiding structure of a long-stroke sliding cover includes a sliding member, a relative sliding member, first elastic assemblies and second elastic assemblies. The sliding member includes first sliding-guided portions having turned curved portions. The relative sliding member includes a second sliding-guided portion and a third sliding-guided portion, wherein the second sliding-guided portion has a sliding track interlaced with the first sliding-guided portion, and the third sliding-guided portion has a sliding track interlaced with an apex of the turned curved portion of the first sliding-guided portion. The first elastic assembly is slidably connected to the first and second sliding-guided portions. The second elastic assembly is slidably connected to the first and third sliding-guided portions. When a short part of an opening stroke of a sliding cover is performed, a subsequent, long part of the opening stroke of the sliding cover can be automatically operated.