To　simulation　accurately　temperature　field　during　laser　keyhole　welding,　a　three-dimensional　transient　mathematical　model　was　developed.　A　volumetric　heat　source　model　was　used;　Melting　and　evaporation　enthalpy,　recoil　pressure,　surface　tension　and　energy　loss　due　to　evaporating　materials　were　considered;　the　enthalpyporosity　technique　was　employed　to　account　for　the　latent　heat　during　melting　and　solidification.　The　results　of　a　three-dimensional,　transient　finite　volume　simulation　of　a　laser　deep　penetration　welding　process　based　on　this　model　were　presented.　Temperature　field　and　weld　pool　shape　were　calculated　using　FLUENT　soft.　The　calculated　weld　dimensions　agreed　reasonable　well　with　the　experimental　results.　The　effectiveness　of　the　developed　computational　procedure　had　been　confirmed.　©　American　Scientific　Publishers　All　rights　reserved.