A　general　finite-element　software　program,　MSC/Marc,　has　been　used　to　develop　a　coupled　thermo-mechanical　model　of　rotary　swaging　process　for　pure　magnesium.　The　emphases　are　on　the　effects　of　the　conical　feeding　angle　a　on　the　rotary　swaging　process.　It　is　concluded　that　the　strain　distribution　turns　more　homogeneous　with　the　increase　of　a　up　to　alpha　threshold　value　alpha(Tres),　then　no　more　influence　on　the　homogeneity　of　the　strain　distribution.　Under　the　technological　conditions　simulated　in　this　article,　the　threshold　value　is　21.7　degrees.　The　strain　distribution　in　the　exterior　cylindrical　surface　exhibits　periodical　pulses　along　the　axial　direction　and　the　pulse-height　enlarges　with　the　increase　of　alpha.　It　is　appropriate　for　9.5　degrees　＜=alpha　＜=　21.7　degrees　under　the　technological　conditions　simulated　in　this　article.　The　simulated　results　agree　well　with　the　experimental　ones.