Abstract： Objective To examine the effects of cholecystokinin octapeptide (CCK-OP), vasoactive intestinal peptide (VIP) and substance P (SP) on the dynamics of the biliary system and cardiovascular system, and the relationship between the dynamics of the biliary system and cardiodynamics.Methods In 91 anesthetized guinea pigs, a triple-lumen, side-hole perfusion catheter (1.0 mmOD) was inserted through the duodenal papilla into the common bile duct (CBD) and the sphincter of Oddi (OS). An end-hole PE-50 catheter was inserted into the left ventricle of heart through the left jugular artery. The left ventricle of heart motility, OS motility and CBD pressure were recorded during the intravenous administration of CCK-OP, VIP, SP and the combination of CCK-OP and VIP.Results Intravenous CCK-OP increased the fasted OS motility index (MI), decreased the basal pressure in OS, increased CBD pressure, and inhibited the motility of the left ventricle of heart. VIP alone showed no significant effect on the biliary system and cardiovascular system, but when infused together with CCK-OP, it inhibited the effects of CCK-OP on both systems. Exogenous SP acted like CCK-OP on both biliary system and cardiovascular system, but less potently.Conclusions The gastrointestinal peptides have important effects on both biliary system and cardiovascular system. There is an important negative correlation between CBD pressure and the motility of the left ventricle of the heart during the infusion of peptides.