Abstract: "Deep hypothermic cardiopulmonary bypass (DHCPB) model was established in piglets. Two grades of perfusion flow rate and two types of prime formula were used to study their influnce on changing rate of body temperature, balance of body fluid，blood hematocrit and colloidal pressure in prime. The results showed that 80ml • kg^-1• min^-1 of perfusion flow rate and pure blood prime were better than 100ml • kg^-1• min^-1 and mixed prime of crystalloid and blood. The results suggested that perfusion flow rate and prime formula should be correctly designed according to the normal physiology of selected animals when DHCPB model was to be established. "

Key words: "Deep hypothermic cardiopulmonary bypass, Prime, Perfusion flow rate, Piglet "