The study is a non-intervention observational study. Purpose of this study is to observe some selected miRNA expression which evaluate the sepsis prognosis in the progression of sepsis . The investigators will collect serum samples from patients with sepsis in SICU, RICU and EICU on the 1st、3rd、5th、7th、10th、14th day of 301 Hospital since November 2011 , and then use mirVana PARIS kit extract total RNA and use qRT-PCR detect miRNAS expression in serum which can evaluate the prognosis of sepsis, and statistical analysis the miRNAS expression correlation with SOFA score.