【Abstract】Objective To investigate the influent factors on normal intraabdominal pressure （IAP） and establish the IAP regressive equation. Methods The IAPs of 106 hospitalized patients were determined through monitoring the bladder pressures. The relationship between IAP and 14 factors including age, gender, height, weight, body mass index （BMI）, previous and recent abdominal surgical history, reasons for admission，complications and their quantities were analyzed，respectively.Results The mean IAP of the hospitalized patients was 5.5 mm Hg with a range from 0.4 mm Hg to 12.8 mm Hg. The difference among IAPs of different grades of BMIs had statistical significance （F=5.550，P＜0.01）. The male IAPs were 2.0 mm Hg higher than the female IAPs，which had statistical significance （t=3.122，P＜0.01）. The other 12 factors had no significant effects on IAP （Pgt;0.05）. Conclusion Normal IAP is possibly influenced by gender and BMI，and it is individually different.