In　experiments　and　calculations　of　the　incremental　transmission　losses-σ,　the　Author　find　that　if　use　the　Matrix　formed　by　double　of　the　line　resistance-2R　to　replace　the　B　matrix　of　DC　power　formed　by　susceptance,　the　result　will　not　be　the　node　voltage　phase　angle　but　be　incremental　transmission　losses-σ.　Then　the　author　use　the　Kirchmaver　five　nodes　example　to　contrast　the　results　of　this　method　with　other　methods:　Shouts＇　Least　Squares,　Podmore＇s　DC　power　flow　and　Jacobian　method.　From　the　Comparison　we　can　prove　the　correction　of　the　method　proposed　in　this　paper.　The　Method　has　many　advantages　such　as　clear　conception,　simple　calculation　process　and　consistent　accuracy,　so　the　method　can　be　used　in　economic　dispatch　and　biding　in　power　market.　©2010　IEEE.