Objectives : CHUNA therapy that removes compression of dislocated vertebral bones has positive effect, but sometimes improper CHUNA manual therapy may give rise to negative effect. The aim of this study is to make sure that cervical CHUNA manual therapy give positive effect or negative effect to the blood flow velocity of vertebral artery(VA) and basilar artery(BA) by Trancranial Doppler sonography(TCD). Methods : We performed TCD study on 20patients(male 5, female 15, mean ages 38.5 years) with diagnosis like cervical movement related disorder, headache or dizziness. After we measured mean blood flow velocity(Vm) of VA and BA before cervical CHUNA therapy(Pre-CCT) and after cervical CHUNA therapy(Post-CCT), statistically evaluated the results. Results: The patients received cervical CHUNA therapy for TA sequel, HIVD of cervical spine, headache, dizziness, neck stiffness etc. VA Vm was $31.9{pm}8.0cm/sec$ before CHUNA therapy, but significantly increased $35.0{pm}8.7cm/sec$ after CHUNA therapy (p < 0.05). But, there was no significant variation of BA Vm between $41.8{pm}7.5cm/sec$ Pre-CCT and $41.2{pm}8.5cm/sec$ Post-CCT(p>0.05). Though VA Vm slightly increased after CHUNA therapy in normal range group, there was no significant variation between VA Vm Pre-CCT and VA Vm Post~CCT. In VA Vm decrease group, VA Vm significantly increased after CHUNA therapy(p<0.05). But, there was no significant variation of BA Vm between Pre-CCT and Post-CCT in BA Vm normal range group and BA Vm decrease group(p>0.05). Conclusions: These findings suggest that cervical CHUNA manual therapy have positive effect on blood flow velocity of VA and BA.