The regulative effect of deep peroneal nerve(DPN) inputs on cardiovascular deceleration and depression responses induced by electric stimulation of rabbit's caudal ventrolateral medulla(CVLM) was observed. Experiments were performied on 30 white male rabbits anaesthetized with chloralose-urethane under artifical ventilation. The results showed that:(1)the inputs of DPN could inhibit the cardlac deceleration response evoked by electric stimulation of CVLM(P<0.0001), and the regulative effectsof DPN disappeared in 25~30 min;(2) afteriv atropine(0.25 mg/kg) or scopolamine(0.25 mg/kg) the heart rate and blood pressure reduction value had no significant difference when stimulated CVLM+DPN compared with control group(P>0.05);atropine or scopolamine could not abolish the inhibitory effect of DPN inputs;(3)after tv naloxone(1.5 mg/kg) or microinjection of naloxone into rostral ventrolateral medulla(RVLM)(2μg in 1 μl NS perside bilaterally),the inhibitory effect of DPN inputs was abolished partly(P<0.01).These results suggest that:(1) the cardiac deceleration and depression responses elicited by CVLM excitation in rabbits can be regulated by inputs of DPN;(2)it seems that the regulative function may have no relationship with acetylcholine system. On the other hand, endogenous opiate peptide in RVLM may take part in inhibitory effect of DPN inputs on cardiovascular effects excited by CVLM.