Abstract:Rats with adjuvant arthritis were used as an animal model of pathological pain inthis experiment and pain threshold was examined by recording the latency of heat -tail flickreflex- The results were as follows:The pain threshold decreased significantly , body temperature and the diameter of the ankle joint of hind leg increased remarkably post inoculation After HAN treatment,the pain threshold increased, while body temperature and the joint diameter decreased significantly The analgesic effect of HAN was enhanced by intraperitoneal injection of Vitamin B6. The results suggest that the adjuvant arthritis could be used as agood model for the study of chronic pain, and HANS did show a good therapeutic effect onadjuvant arthritis in rats,which seemed to be improved by the injection of Vitamin B6.