OBJECTIVE To investigate mycoplasma infection in ICU patients.METHODS Sixty-five samples from blood,respiratory tract and genitourinary tract of patients were collected respectively from Oct 2007 to July 2008 in ICU.Mycoplasma pneumoniae(Mp),Urealasma urealytium(Uu) M.fermentans(Mf) and M.penetrans(Mpe) were cultivated by modified mycoplasma fluid and solid medium.Mf and Mpe positive isolates were verified by nested polymerase chain reaction(rPCR),Mp and Uu were confirmed by fluorescent quantitative PCR.RESULTS It was found that the positive detection rate for Mp was 12.3%(8/65)in blood and 35.4%(23/65) in respiratory tract excreta and for Mu 1.5%(1/65) and 26.2%(17/65) in blood or Genitourinary tract,respectively.Mpe and Mf did not detected.CONCLUSIONS The state of mycoplasma infection is very severe,and often accompanies bacterial infection.It is necessary to consider mycoplasma when chose antibiotics.