Objective To explore the relationship between the stimulating quantity of acupuncture and its effect on cervical sympathetic discharge in stress-induced hypertensive rats.Methods Totally 110 male Wistar rats were randomized into A

B

C

D

E

F

G

H

I

J and K groups with 10 ones in each.Stress-induced hypertension models were established in all the animals by electric shock to the feet and noisy stimulus except group A.Group A and B were used as control groups

and the others accepted different stimulation quantity of acupuncture in Quchi（LI 11） with different twirling parameters of angle

frequency and time.Cervical sympathetic discharge signals were collected by bioelectrical device to record the score amplitude and frequency histogram of discharge before and after treatment.Results After acupuncture

in group F and J

the discharge scores and histogram were both increased with a significant difference（P<0.01 or P<0.05）

while in group K

the discharge scores and histogram were decreased with a significant difference（P<0.01）.Conclusion The experiment shows that the needle twirled right for 3 circles and 2 circles exerts an inhibiting function and twirled left for 2 circles produces an exciting function on cervical sympathetic nerve

proved the objective existence of left twirling as reinforcing and right twirling being reducing.