Abstract： Objective To analyze the risk factors of prognosis in elderly patients with septic shock in ICU.Methods Clinical data of 113 elderly patients with septic shock admitted in the ICU of Ningbo Medical Center Lihuili Eastern Hospital from November 2015 to March 2019 were retrospectively analyzed. Among them, 40 patients died ( death group) and 73 patients survived (survival group) within 28 d after diagnosis confirmed.The general information ,underlying disease,laboratory findings and invasive operations were compared between the two groups.Multivariate Logistic regression was used to analyze the risk factors for prognosis of patients, and ROC curve was used to analyze the predictive value of risk factors for death . Results Multivariate Logistic regression analysis showed that APACHEII score ( OR ＝1.344, 95%CI 1畅187-1.520,P＜0.01) and lactic acid level at admission (OR＝1.311,95%CI 1.075-1.599,P＜0.01) were independent risk factors for prognosis ,while platelet counts (OR＝0.986,95%CI 0.976-0.996,P＜0畅01)and albumin level(OR＝0.812,95%CI 0.697-0.945,P＜0.01)were protective factors for prognosis. ROC curve analysis showed that the area under the curve of APACHEII score ,lactic acid level at admission and APACHEII score combined with lactic acid level at admission were 0.861(95%CI 0.784-0畅919,P＜0畅01),0.752(95%CI 0.662-0.828,P＜0.01) and 0.904(95%CI 0.834-0.951,P＜0.01),respectively. The predictive value of APACHEII score combined with lactic acid level at admission was better than those of APACHEII score and lactic acid level at admission ( Z ＝2.175 and 2.879, P ＜0.05 and P ＜0畅01). Conclusions Lower APACHEII score and lactic acid level ,increased platelet counts and albumin level may be associated with a favorable prognosis for elderly patients with septic shock .APACHEII score combined with lactic acid level at admission has better predictive value for prognosis .