Abstract: Objective: To evaluate the predictive value of the change rate of sublingual microcirculation indexes on the prognosis of patients with septic shock. Methods: A total of 64 patients with septic shock were retrospectively collected,and divided into death group (n=23) and survival group (n=41) according to different outcomes 28 days after treatment.Treatment and early fluid resuscitation were given according to the 6-hour bundle regimen.MAP,terminal filling time,ScvO₂,P(v-a)CO₂,total positive balance of liquid,lactic acid clearance,PaO₂/FiO₂ and sublingual microcirculation before and after 6 h of resuscitation were observed and recorded. Results: The 6-hour lactatic acid clearance,PVD and PPV change rates were higher in the survival group than those in the death group,and the lactatic acid concentration was lower than that in the death group,and the difference was statistically significant (P<0.05 to P<0.01).Lactic acid clearance had the highest predictive value for 28-day survival,with an area under the curve of 0.941,a sensitivity of 82.9%,a specificity of 96.7%,and an optimal cut-off value of 57.00%.The next was the PPV change rate,with an area under the curve of 0.789,a sensitivity of 68.3%,a specificity of 82.6%,an optimal cut-off value of 2.8%,and an area under the PVD curve of 0.649 for 6 h of resuscitation,a sensitivity of 73.2%,a specificity of 56.5%,and an optimal cut-off value of 8.87%. Conclusions: Lactatic acid clearance,PPV change rate and PVD indexes can sensitively reflect the improvement of microcirculation,and have predictive value for the prognosis of patients with septic shock.