The　article　builds　a　three-stage　game　model　to　analyze　how　the　enterprises＇　financing　strategy　affects　their　technology　innovation　activity　with　spillover　effect　and　quantity　decision　when　they　form　technology　innovation　alliance.　We　show　that　the　enterprise＇s　innovation　activity　is　negatively　affected　by　the　technology　innovation　spillover　and　positively　affected　by　its　debt　financing　strategy;　the　equilibrium　saving　cost　and　the　equilibrium　profit　under　being　debt　financing　both　are　lower　than　them　under　not　being　debt　financing.　However,　the　equilibrium　quantity　is　dependent　on　spillover　effect.　©2009　IEEE.