Objective:To compare intraoperative use of gelatin and hydroxyethyl starch 130/0.4 in elderly severe patients undergoing coronary artery bypass surgery, in terms of volume expansion efficiency, side effects and clinical prognosis. Methods: Forty severe patients aged ≥60 years old undergoing coronary artery bypass surgery were randomized to receive intraoperative gelatin (n=20) or HES130/0.4 (n=20) as volume replacement. Amount of crystalloid and colloid solution, blood coagulation, bleeding, blood products infusion, serum creatinine, and time for tracheal tube extraction, length of stay in ICU and hospital were measured and compared. Results: Intraoperative amount of gelatin was slightly less than HES130/0.4 (P=0.35), while amount of crystalloid solution needed between groups was comparable. No significant difference of blood coagulation, bleeding and blood products infusion was found between groups. Serum creatinine increased transiently in both groups to a comparable extent on the 1st POD, and subsequently decreased to normal on the 4th and 7th POD, with no difference between groups at each time point. Time for tracheal tube extraction and length of stay in ICU did not differ significantly between groups, while hospital length of post-operative stay was longer but not significantly in Gelatin group compared to HES130/0.4 group. Conclusion: In elderly severe patients undergoing coronary artery bypass surgery, intraoperative volume therapy with gelatin or HES130/0.4 showed no significant difference between groups in terms of both volume expansion efficiency and side effects like blood coagulation and renal function.