Submarine　pipeline　is　widely　used　for　the　transportation　of　oil　and　gas　in　offshore　exploration　and　production.　The　free　span　of　pipeline　is　inevitable　because　of　the　complex　seabed　conditions,　which　may　result　in　the　upheaval　buckling　failure　under　the　service　conditions.　In　this　paper,　several　experimental　tests　on　scale　models　of　submarine　pipelines　was　carried　out.　The　test　results　show　that　the　length　of　the　free　span　is　closely　related　with　the　buckling　of　the　pipeline.　The　upheaval　buckling　of　pipelines　is　induced　by　the　high　compressive　stress　due　to　thermal　action　and　triggered　by　the　initial　curvature　due　to　self-weight.　Thus,　the　traditional　analysis　and　design　method　with　effective　length　method　cannot　be　used.　Based　on　the　experimental　results,　a　simple　and　effective　finite　element　model　is　developed　and　verified　for　parametric　study.　The　numerical　simulation　results　show　that　the　diameter,　length　of　free　span　and　the　self-weight　of　the　pipeline　will　influence　the　buckling　resistance　of　the　pipeline　system.　The　proposed　finite　element　model　can　be　used　for　the　practical　design　of　submarine　pipelines.　Copyright　(C)　2019　by　The　Hong　Kong　Institute　of　Steel　Construction.　All　rights　reserved.