Abstract： Objective:To study the role of serum long non-coding RNA small nucleolar RNA host gene 5 (lncRNA SNHG5) in assessing disease severity and in prognosis in children with acute respiratory distress syndrome (ARDS).Methods:This was a cohort study.Non-random sampling method was used.Ninety-eight children with ARDS in the Newborn Department of Hunan Aerospace Hospital were selected as study subjects.According to the first chest radiograph results of children with ARDS and the severity of the disease, they were divided into mild group (26 cases), moderate group (39 cases), and severe group (33 cases); according to the prognosis during hospitalization, the children were classified into good prognosis group (75 cases) and poor prognosis group (23 cases). qRT-PCR was used to measure the serum lncRNA SNHG5 level; ROC curve was drawn to analyze the value of serum lncRNA SNHG5 level in predicting the prognosis of children with ARDS; multivariate Logistic regression was used to analyze the influencing factors of poor prognosis in children with ARDS.Results:The level of lncRNA SNHG in children with ARDS of different disease severity was statistically significant ( F=42.51, P<0.001). The level of serum lncRNA SNHG in severe group (0.27±0.09) was lower than that in moderate group (0.45±0.16) and mild group (0.64±0.20), with the level in moderate group lower than that in mild group ( P<0.05). The level of serum lncRNA SNHG5 in poor prognosis group (0.29±0.09) was lower than that in good prognosis group (0.46±0.18)( t=4.35, P<0.001). The proportion of premature rupture of membranes in poor prognosis group was lower than that in good prognosis group, with 8.70% (2/23) vs 38.67% (29/75), ( χ2=7.31, P=0.007). The proportion of pregnancy induced hypertension in poor prognosis group was 26.09% (6/23), higher than that in good prognosis group 1.33% (1/75), ( χ2=16.26, P<0.05). When the optimal cut-off point of serum lncRNA SNHG5 level was 0.34, the area under the curve to predict the poor prognosis of children with ARDS was 0.832 (95% CI: 0.751-0.913), the sensitivity was 76.0%, and the specificity was 87.0%.Increased lncRNA SNHG5 is a protective factor for poor prognosis in children with ARDS (95% CI: 0.725-0.954, P=0.009). Conclusions:Decreased level of serum lncRNA SNHG5 can lead to disease progression and poor prognosis of children with ARDS, and it has a high value for prognosis evaluation.