Experiments were performed on 36 anesthetized rabbits. By cervical vagal afferent stimulation (VAS) with lower electric frequency (5-8 Hz) and higher electric frequency (50-100 Hz), the depressor and pressor responses were established. Both of these responses accompanied by decreasing in renal sympathetic activity (RSA). With the parameters of vagal-pressure reflex and vagal-sympathetic stimulation reflex, effects of stimulation of the locus coeruleus on these were investigated. The vagal-pressure and sympathetic reflexes were significantly inhibited by electric and chemical (glutamate) stimulation of the locus coeruleus. Meanwhile both the electric and chemical stimulation of the locus coeruleus per se elicited the elevation of BP and RSA. These results together with the recently hypothesized global function of the locus coeruleus were discussed.