Objective To study the clinical characteristics of septic patients in general intensive care unit. Methods To retrospectively analyze clinical data of 912 cases with sepsis admitted to the ICU of our hospital during 2005-2006, and to compare clinical characteristics of patients with severe sepsis, septic shock and non-sepsis. In addition, the site of primary infections in the patients with sepsis were investigated. Results There were significant differences in average age, the length in ICU, APACHEⅡ scores, the usage frequency of ventilator and mortality between patients with severe sepsis or septic shock and non-sepsis (P0.01); There was positive correlation between age, APACHEⅡ score and mortality in the patients with severe sepsis; Compared with other causes, the mortality of sepsis as a result of infection from respiratory system showed a significant difference (P0.01). Conclusions Sepsis occurs generally in the ICU, especially clinical characteristics such as old age, severity of illness and higher mortality in patients with severe sepsis is evident; The proportion is high for patients with sepsis as a result of infection from respiratory system,which affects the prognosis of patients.