Abstract： Objective To investigate the advantages and disadvantages of modified water sac method and intraperitoneal perfusion for establishment of liquid animal model with high intra-abdominal pressure.Methods Twenty healthy adult New Zealand rabbits were randomly divided into two groups (n=10 each).Group Ⅰ was given intraperitoneal perfusion to establish liquid animal models with high intra-abdominal pressure.Group Ⅱ was treated with water sac method to establish modified liquid animal models with high intra-abdominal pressure.The infusion volume and the corresponding abdominal pressure were measured,and the pressure-capacity curve was drawn.When the intra-abdominal pressure was 10,20,30,40,and 50 cmH2O (1 cmH2O=0.098 kPa),the infusion volume of normal saline was recorded.Results The pressure-volume curve of the animal models with high intra-abdominal pressure showed a positive correlation between abdominal pressure and infusion volume in the two groups of animal models.Group Ⅰ (perfusion model) regression equation:y=-68.84 + 0.0762x (R2=0.9068,P=0.0001).Group Ⅱ (water sac model) regression equation:y=-132+0.1643x (R2=0.8023,P=0.0064).When the intra-abdominal pressure was 10,20,30,40 and 50 cm H2O,the infusion volume of water sac method was significantly less than that of perfusion method [(920±35.28) ml vs (1 070±60.54) ml,(970±40.44) ml vs (1 26064.62) ml,(1 000± 41.36) ml vs (1 370±65.28) ml,(1 025±44.22) ml vs (1 470±68.68) ml,(1 045±48.60) ml vs (1 520± 75.76) ml],all P＜0.01.Conclusion The animal model with high intra-abdominal pressure established by modified water sac method is a new animal model better than that established by intraperitoneal perfusion.It justifies use for reference in establishing animal models of high intra-abdominal pressure in clinical research.