Objective:　To　investigate　the　effect　on　aneurysmal　pressure　after　stent　intervention　treatment　for　aneurysm　accompanied　by　stenosis.　Methods:　Computational　fluid　dynamics　(CFD)　analyses　were　carried　out　to　make　comparative　study　on　aneurysm　models　with　and　without　stenosis.　Three　models　(M1,　M2,　M3)　were　constructed　to　compare　the　pressure　variations.　M1　was　the　aneurysm　model　with　no　stenosis　and　no　stent,　M2　was　forming　from　M1　model　with　a　preaneurysm　stenosis,　and　M3　was　the　M2　model　with　stent　implantation　at　the　place　of　the　aneurysm.　Results:　For　comparison　between　M2　and　M1,　pressure　increase　in　the　aneurismal　sac　caused　by　a　mild　stenosis　(50%)　was　about　1.399　9　kPa(10.3　mmHg)　with　the　peak　systole,　and　the　average　pressure　increase　in　a　cardiac　cycle　was　about　0.572　kPa(4.3　mmHg).　For　comparison　between　M2　and　M3,　pressure　increase　in　the　aneurismal　sac　was　about　1.037　kPa(7.8　mmHg)　at　peak　systole　in　a　cardiac　cycle,　and　the　average　pressure　increase　in　the　aneurismal　sac　in　a　cardiac　cycle　was　about　0.399　kPa(3　mmHg).　Conclusions:　A　mild　stenosis　could　not　result　in　the　sharp　pressure　increase　with　stent　intervention　applied　to　the　treatment　of　aneurysm　accompanied　by　stenosis　harbored　on　a　tortuous　intracranial　artery.　The　geometry　of　the　parent　vessel　and　its　aneurysmal/stenotic　diseases　do　have　influence　on　the　pressure　variation　at　the　place　of　aneurysm.