Objective: To investigate the relationship among plasma endothelin(ET), calcitonin gene-related peptide(CGRP) and blood flow rate of bilateral vertebral arteries in patients with cervical vertigo(CV) and to assess the effect of ET and CGRP on the onset of CV. Methods:The concentration of ET and CGRP in 64 patients with CV and 30 controls was determined by radioimmunity method. The average blood flow velocity (Vm) of bilateral vertebral arteries was detected by Transcranial Doppler(TCD). Results:Plasma concen-tration of ET(91.48±9.08 pg/ml) and ET/CGRP ratio value(2.88±0.52) in vertebrobasilar arteriospasm group were both higher than those in vertebrobasilar non-arteriospasm group and in controls, while CGRP concentration(30.66±6.05 pg/ml) in vertebrobasilar arteriospasm group was lower than that in vertebrobasilar non-arteriospasm group and controls respectively. The Vm of bilateral verte-bral arteries in vertebrobasilar arteriospasm group(67.97±11.64 cm/s ) was higher than that in vertebrobasilar non-arteriospasm group and controls respectively, having a positive correlation with ET concentration and ET/CGRP ratio value(r1=0.52, P < 0.05; r2=0.59, P < 0.05), but a negative correlation with CGRP concentration(r3=-0.54, P < 0.05). There was no significant difference in ET and CGRP concentration, ET/CGRP ratio value and the Vm of bilateral vertebral arteries between vertebrobasilar non-arteriospasm group and the control group. Conclusion: All the results indicate that ET and CGRP are possibly the most important substance factors at the onset of CV with vertebrobasilar arteriospasm, and their imbalance of regulating vertebrobasilar arterial contraction and relaxation may play an important role in the onset of CV with vertebrobasilar arteriospasm.