Fructus Aristolochiae has been used in Korea for many centuries as a treatment for various disease.The purpose of the present study is to determine the effect of Fructus Aristolochiae on norepinephrine(NE) induced blood vessel contraction in rabbits. Rabbit(2 kg, male) were killed by $CO_2$ exposure and a segment (8-10mm) of each rabbit was cut into equal segments and mounted in a tissue bath. Contractile force was measured with force displacement transducers under 2-3 g loading tension. The dose of norepinephrine(NE) which evoked 50% of maximal response ($ED_{50}$) was obtained from cumulative dose response curves for NE ($10^{-6}{sim}10^{-3}M$). Contractions evoked by NE ($ED_{50}$) were inhibited significantly by Fructus Aristolochiae in abdominal aorta and femoral artery. Fructus Aristolochiae inhibited the relaxation pretreated propranolol and L-NNA in femoral artery. But Fructus Aristolochiae did not effect the relaxation pretreated ODQ in femoral artery and abdominal aorta. These results indicate that Fructus Aristolochiae can relax NE induced contraction of rabbit blood vessel selectively, and that this relaxation relates to nitric oxide synthesis and sympathetic action.