Objective:To explore the value of lung ultrasound(LUS)score combined with peripheral blood procalcitonin(PCT),C-reactive protein(CRP)and interleukin-6(IL-6)levels on evaluation of disease severity and prognosis of patients with acute respiratory distress syndrome(ARDS).Methods:109 patients with ARDS were selected.The disease severity and progno-sis of patients were grouped according to the Berlin criteria for ARDS.The baseline data were compared among mild group(n=24),moderate group(n=55)and severe group(n=30).According to the prognosis,they were divided into a survival group(n=68)and a death group(n=41).The differences in LUS score,peripheral blood PCT,CRP and IL-6 levels among the three groups and patients with different prognoses were analyzed,and the evaluation value of the above indexes on the disease severity and prognosis was analyzed.Results:There were statistical differences in prognosis and APACHE Ⅱ score among the three groups(P<0.05).The survival rate of patients in severe group was lower than that in moderate group(P<0.05),and the rate in moderate group was lower than that in mild group(P<0.05).The APACHE Ⅱ score of patients in severe group was higher than that in moderate group(P<0.05),and the score in moderate group was higher than that in mild group(P<0.05).The LUS score and peripheral blood PCT,CRP and IL-6 levels revealed statistical differences among ARDS patients with different disease severities(P<0.05).The severe group was higher than the moderate group(P<0.05),and the moder-ate group was higher than the mild group(P<0.05).Spearman analysis showed that LUS score and peripheral blood PCT,CRP and IL-6 in ARDS patients were positively correlated with disease severity(P<0.05).The LUS score,PCT,CRP and IL-6 in death group were higher than those in survival group(P<0.05).After Logistic regression analysis,it was found that A-PACHE Ⅱ score,LUS score,PCT,CRP,IL-6 and disease severity were the influencing factors of prognosis in patients with ARDS(P<0.05).ROC curve results showed that the areas under the ROC curves of LUS score,peripheral blood PCT,CRP and IL-6 and combined detection for predicting the death prognosis in ARDS patients were 0.778,0.781,0.864,0.856 and 0.982,and the sensitivities were 75.61％,78.05％,90.24％,80.49％and 92.68％,respectively.The combined detection value was higher.Conclusion:LUS score and peripheral blood PCT,CRP and IL-6 levels can effectively evaluate the disease severity of ARDS patients,and have reliable predictive value for prognosis of patients.