Objective: To explore the effects of different infusion schemes on colloid osmotic pressure during major abdominal surgery and perioperative albumin in elderly patients. Methods: 140 elderly patients of 65-80 years old undergoing major abdominal surgery were divided into 4 groups according to the method of random number table , and different proportions of crystals and colloids were given to different groups (group A: whole crystal, group B: crystal-colloid ratio 1 : 1, group C: crystal-colloid ratio 2: 1, Group D: crystal-colloid ratio 1: 2). The plasma colloid osmotic pressure and level of albumin during perioperative period were monitored. Simultaneously observe the arterial blood pH, blood glucose, extubating time of endotracheal tube, postoperative feeding time, et al. Results: The total amount of liquid inputted in the group of whole crystal was 3056ml (3056 ± 253), which was significantly increased compared with other groups (P<0.01). At the same time, the colloid osmotic pressure decreased by 11.9 mmHg (11.9 ± 2.8), which was more obviously decreased than that of the other groups( B group3.9 ± 1.3, C group 1.5 ± 0.3, D group 4.7±2.1). The difference was a statistically significant(P<0.01). On the other day after surgery, the level of albumin decreased by an average of 4.3 g / L (4.5 ± 1.9) compared with that in group B before surgery, and group C decreased by 2.9 g / L (2.9 ± 1.2) in average, which was significantly different (P<0.05) from group A 10.2 g / L (10.2 ± 1.8). There was no statistically significant difference between group A and group D (P>0.05). And the other indexes were not significantly different between the two groups. Conclusion: This study found that different infusion solutions with different crystal-colloid ratios had an effect on perioperative colloid osmotic pressure and level of albumin.