In　the　present　study,　magnetic　properties　and　demagnetization　processes　of　Co　nanowires　with　various　morphologies　(ellipsoids,　capped　cylinders,　and　cylinders)　are　investigated　by　means　of　Object　Oriented　Micromagnetic　Framework　(OOMMF)　software　package　with　finite　difference　micromagnetic　simulation.　The　results　show　that　the　aspect　ratio,　morphology,　and　dipolar　interactions　of　the　nanowires　play　a　key　role　in　determining　the　switching　modes　and　hence　the　magnetic　properties.　For　the　Co　nanowires　with　the　same　morphology　and　diameter,　the　coercivity　increases　substantially　with　increasing　aspect　ratio　of　the　nanowires　due　to　the　increased　shape　anisotropy　when　the　aspect　ratio　is　less　than　3.　For　a　single　nanowire　with　a　fixed　diameter　of　15　nm　and　a　length　of　200　nm,　the　coercivity　of　ellipsoids　of　14.45　kOe　is　noticeably　higher　than　those　of　capped　cylinders　of　12.55　kOe　and　cylinders　of　11.15　kOe,　indicating　the　considerable　influence　of　the　morphology　on　the　coercivity　of　the　wires.　The　magnetization　reversal　mechanism　of　a　single　Co　nanowire　is　mainly　described　by　a　nucleation　propagation　process,　which　starts　at　the　ends　of　the　nanowires.　For　the　nanowires　assembly,　the　magnetic　moment　reversal　of　some　nanowires　occurs　first,　and　the　rest　reverse　gradually　with　increasing　applied　field　and　ultimately　the　reversal　of　the　whole　assembly　is　achieved.　This　process　could　be　theoretically　interpreted　based　on　the　nucleation　of　closure　domains　at　the　ends　of　the　wires　as　well　as　the　subsequent　depinning　and　propagation　of　domain　walls.　Meanwhile,　the　squareness　of　the　demagnetization　curve　and　coercivity　of　the　nanowires　assembly　deteriorate　faster　than　those　of　the　single　nanowires　due　to　the　dipole　interactions.