The study is a non-intervention, prospective observational study. Purpose of this sudy is to screening several miRNAs by microarray which can evaluate the prognosis of sepsis . We will collect serum samples from patients with sepsis in SICU, RICU and EICU of 301 Hospital since September 2009 , and then use the chip and qRT-PCR to Screen miRNAs which can evaluate the prognosis of sepsis, and statistical analysis the miRNAS expression correlation with SOFA score.