Abstract: Objective To explore the clinical value of procalcitonin (PCT) in patients with sepsis caused by different pathogens. Methods 65 patients diagnosed with sepsis were involved in this study. The test data such as serum PCT, CRP, WBC and blood culture were collected. These data from bacterial and virus groups, G+ and G- groups, sepsis, severe sepsis and sepsis shock groups were compared respectively. Results The serum PCT level in bacterial group and G- group were significantly higher than in virus group and G+ group. The serum PCT level in sepsis shock group was also significantly higher than in sepsis or severe sepsis group. No statistically significant difference was found in CRP and WBC among these groups. Conclusion Clinical benefits of using PCT to distinguish different pathogens and categorize severity of sepsis in infected patients had been proved, which might provide effective reference for clinical treatment in early stage and prognosis for sepsis.