Sepsis is a leading cause of death in critically ill patients.The definitions of sepsis and septic shock were introduced in 1991 and last revised in 2001.Since considerable advances had occurred to its pathophysiology and management, an update definitions for sepsis and septic shock were released in February 2016 by the Society of Critical Care Medicine and the European Society of Intensive Care Medicine.This article is to review the development and limitations of previous versions of sepsis definition, and summarize the sepsis 3.0 definition and its clinical diagnosis criteria.These updated definitions and clinical criteria will play vital roles in providing important reference frame for clinical trials, and facilitating early recognition and timely management of patients with sepsis.

Sepsis; Shock, septic; Diagnosis