Abstract： Objective To evaluate the supportive effects on cardiopulmonary failure in critically ill patients treated with extracorporeal membrane oxygenation (ECMO).Methods A retrospective observational study of 9 patients treated in intensive care unit (ICU) of Peking University Third Hospital and Beijing Ditan Hospital from October 1,2007 to December 26,2009 with ECMO for various diseases was conducted.Clinical data was analyzed.Results Of 9 patients [mean age (26.8 ± 7.0) years,body mass index (28.3 ± 9.1 ) kg/m2] were enrolled,3 were male and 6 were female.Two patients were treated with veno-arterial (V-A) ECMO for severe heart failure,and 7 with veno-venous (V-V) ECMO due to refractory acute respiratory distress syndrome ARDS caused by 2009 novel H1N1 virus infection.The doses of vasoactive agents and cardiac parameters changed greatly after the V-A mode.The setting of ventilator support were significantly decreased,and arterial oxygen saturation (SaO2),arterial blood carbon dioxide partial pressure (PaCO2) and blood pH value were improved significantly after the V-V mode ECMO.Acute renal insufficiency occurred in 5 patients,hyperbihrubinemia in 6 patients, and catheter related blood stream infection in 4 patients.Five patients were weaned from ECMO successfully and 4 of them rehabilitated,the treatment was withdrawn in 2 patients,and the other 2 patients died during the procedure.The mean amount of red blood cell suspension administered per patients was (15.1 ±9.9) U,and length of ICU stay was (18.9± 15.7) days.Conclusions ECMO has a rapid effect to temporarily support heart or lung function (partially or totally ) during cardiopulmonary failure,leading to organ recovery.Attempts to reduce the incidence of complications might improve the prognosis of critically ill patients.