Objective:　To　provide　reference　for　understanding　the　stress　state　of　the　aortic　arch,　select　the　appropriate　constitutive　relation,　further　analyze　the　biomechanical　properties　of　human　aortic　arch　so　as　to　offer　the　biomechanical　basis　for　treating　aortic　arch　in　clinic.　Method:　Under　two　different　constraints(the　first　constraint:　the　constraint　along　with　the　direction　of　ascending　aorta;　the　second　constraint:　the　ascending　aorta　could　move　freely,　but　the　end　was　closed　with　a　hemisphere),　three　constitutive　relationships　(linear　constitutive,　exponential　function　constitutive,　M-R　constitutive)　and　two　loads(10.67　kPa　and　26.66　kPa),　the　circumferential　stress　on　human　aortic　arch　were　studied　by　the　finite　element　method,　and　the　results　were　also　discussed.　Results:　The　models　under　two　constraints　were　established　and　the　contour　plot　of　circumferential　stress　and　its　distribution　along　the　arc　of　aortic　arch　under　two　constraints,　three　constitutive　relationships　and　two　loads　were　obtained　respectively.　Conclusions:　The　exponential　function　constitutive　model　could　reflect　the　mechanical　properties　of　aortic　arch　more　comprehensively　and　the　mechanical　properties　of　aortic　arch　could　be　reflected　more　factually　under　the　second　constraint.