In　this　paper,　an　improved　minimum　total　path　loss　(MTP)　method　combining　with　power　allocation　is　proposed　for　the　relay　node　selection.　Single-relay　assisted　single-carrier　frequency-division　multiple-access　(SC-FDMA)　for　uplink　transmissions　is　characterized.　For　the　sake　of　exploiting　the　benefits　of　the　proposed　method,　we　investigate　both　the　direct　transmission　as　well　as　the　traditional　MTP　and　the　improved　MTP　cooperative　transmission　under　the　condition　of　amplify-and-forward　(AF)　cooperative　strategy.　Our　simulation　results　show　that　both　the　bit-error-rate　(BER)　and　the　transmission　reliability　of　the　system　of　the　improved　MTP　algorithm　have　been　improved　greatly.　In　addition,　the　transmission　power　is　reduced.　©　2011　IEEE.