Objective To investigate the effect of the different position on hemodynamic moni-tored by FloTrac/Vigileo system in patients undergoing laparoscopic appendectomy.Methods Sixty patients undergoing laparoscopic appendectomy,ASA Ⅰ or Ⅱ,were randomly divided into three groups (n=20):group A,B and C underwent the trendelenburg position of 10 degrees,20 degrees and 30 degrees,respectively.HR,MAP,cardiac output (CO),cardiac index (CI)and stroke volume (SV)were recorded before pneumoperitoneum (T0 ),1 min after pneumoperitoneum (T1 ),5 min af-ter trendelenburg position (T2 ),20 min after pneumoperitoneum (T3 ),1 min after the end of pneu-moperitoneum (T4 )and 5 min after the end of trendelenburg position (T5 )after induction of anesthe-sia.The time of pneumoperitoneum and operation was recorded.Results Compared with T0 ,HR and MAP increased significantly at T1-T3 in three groups(P<0.05);Compared with group C,CO and SV decreased significantly at T2-T3 in group A and group B (P<0.05).Compared with T1 ,CO and SV increased at T2-T3 in group C (P<0.05).Compared with group C,the time of pneumoperitoneum and operation was longer in group A and B (P<0.05).Conclusion During the operation of laparo-scopic appendectomy,the change of the hemodynamic is in clinical safe range,and the time of pneu-moperitoneum and operation is shorter in the position of 30°than 10°and 20°in laparoscopic appen-dectomy.