The　temperature,　the　heat　flux,　and　the　temperature　gradient　in　an　InGaAs　system　vertical-external-cavity　surface-emitting　laser　are　numerical　studied　by　the　use　of　the　finite　element　method,　and　the　analysis　is　focused　on　the　maximum　temperature　rise　in　the　active　region　under　various　conditions.　The　effect　of　substrate　thickness　on　the　peak　gain　of　quantum　wells,　the　influence　of　pump　spot　radius　on　the　maximum　output　power,　and　the　spontaneous　emission　wavelength　under　different　pump　power　are　examined　respectively.