Abstract: Objective To study clinical significance of NLR,PLR and RDW in the diagnosis,dynamic monitoring and prognosis of septic shock. Methods One hundred and fifty-five cases of septic shock（group death：76 deaths,cured group：79 cases）and 155 cases of healthy control were subjected to NLR,PLR and RDW blood testing. A comparison was made in PCT,WBC,RDW,PLR and NLR for their efficiency in diagnosis of septic shock. Results PCT,WBC,RDW,PLR and NLR tests in cases group revealed a statistical significance. The diagnostic sensitivity and specificity were 96.1% and 95.5%,respectively when 4.68 was taken as NLR diagnosis threshold,and 72.3% and 66.4%,respectively when 14.62 was used as PLR threshold. PCT had significantly positive correlation with NLR and PLR（r=0.884,0.599）. The mortality of septic shock was 49.03%. A difference was seen between PCT and RDW in deaths and cured individuals. Patient outcome had positive correlation with PCT and RDW（r=-0.165,-0.449）.Conclusion NLR and PLR had positive correlation with PCT,that can be used to for diagnosis and dynamic monitoring in septic shock patients due to their convenience,economy,and easy application.

Key words: Septic shock, Procalcitonin, Neutroplhil to lymphocyte ratio, Platelet to lymphocyte ratio, Red blood cell distribution width