In　order　to　meet　the　needs　of　the　collaboration　work　between　different　virtual　organizations　in　the　grid　computing,　the　workflow　as　an　important　means　to　implement　cooperation　of　services　was　introduced.　Furthermore,　in　order　to　provide　the　quality　of　service　(QoS)　for　fulfilling　customer　expectations　in　workflow,　a　QoS　based　negotiation　model　including　four　typical　modules　in　the　grid　computing　was　proposed,　which　could　evaluate　the　users＇　requirements　and　return　the　evaluation　results　through　defining　the　message　type　and　designing　the　state　transfered　diagram　based　on　WSDL　specification.　Finally,　through　implementing　the　assessments　of　user　requirements　and　returning　the　results　of　the　assessment　to　the　user,　this　model　promises　that　the　workflow　can　be　closely　around　the　user＇s　requirements　and　improve　the　accuracy　of　choosing　services　to　avoid　service　invalidation.