Background:　Left　ventricular　assist　device　(LVAD)　has　become　an　alternative　treatment　for　end-stage　heart　failure　patients.　Series　type　of　LVAD,　as　a　novel　LVAD,　has　attracted　more　and　more　attention.　The　hemodynamic　effects　of　series　type　LVAD　on　aortic　blood　pattern　are　considered　as　its　important　characteristics;　however,　the　precise　mechanism　of　it　is　still　unclear.　Methods:　To　clarify　the　hemodynamic　effects　of　series　type　LVAD　on　aortic　blood　flow　pattern,　a　comparative　study　on　the　aortic　blood　flow　pattern　and　hemodynamic　states　were　carried　out　numerically　for　two　cases,　including　series　type　LVAD　support　and　normal　condition.　The　steady-state　computational　fluid　dynamic　(CFD)　approach　was　employed.　The　blood　flow　streamline,　blood　velocity　vector　and　distribution　of　wall　shear　stress　(WSS)　were　calculated　to　evaluate　the　differences　of　hemodynamic　effects　between　both　conditions.　Results:　The　results　demonstrated　that　the　aortic　flow　pattern　under　series　type　LVAD　showed　significant　different　from　that　of　normal　condition.　The　strength　of　aortic　swirling　flow　was　significantly　enhanced　by　the　series　type　LVAD　support.　Meanwhile,　the　rotating　direction　of　swirling　flow　under　LVAD　support　was　also　dominated　by　the　rotating　direction　of　series　type　LVAD.　Moreover,　the　blood　velocity　and　WSS　under　LVAD　support　were　also　significantly　enhanced,　compared　with　that　under　normal　condition.　Conclusion:　The　hemodynamic　states,　including　the　aortic　swirling　flow　characteristic,　was　significantly　dominated　by　LVAD　support.　Present　investigation　could　provide　not　only　a　useful　information　on　the　vascular　complications　caused　by　LVAD　support,　but　also　provide　a　useful　guide　for　optimal　the　structure　of　the　series　type　LVAD.