On　the　basis　of　the　gear　pair　integrated　error　proposed　by　the　authors　in　the　past,　a　new　computing　and　evaluating　method　of　gear　meshing　impact　was　introduced　to　effectively　overcome　the　existing　problems　of　present　research　on　gear　meshing　impact.　The　emerging　process　of　meshing　impact　of　the　gear　with　manufacturing　errors　was　explained,　and　three　parts　of　teeth　transition　characteristic　were　researched.　Six　fundamental　types　of　teeth　transition　process　and　their　criteria　were　proposed.　The　relationship　between　the　teeth　transition　types　and　gear　meshing　impact　and　the　variation　rules　of　teeth　transition　under　load　were　introduced.　Based　on　the　above　results,　the　gear　meshing　impact　evaluation　system(GMIES)was　developed.　The　theoretical　and　simulational　studies　showed　that　the　new　method　would　be　a　new　way　to　research,　evaluate　and　control　gear　meshing　impact.