Abstract: Objective To study the expression of serum long non-coding RNA （LncRNA）-HOTAIR in patients with acute pancreatitis and to explore its clinical significance. Methods A total of 80 patients with “acute pancreatitis” admitted to Tongchuan People's hospital from January 2018 to December 2019 were selected and divided into mild acute pancreatitis （MAP）, moderate severe acute pancreatitis （MSAP） and severe acute pancreatitis （SAP） according to whether the patients met the diagnostic criteria of “severe acute pancreatitis”, including 20 cases in MAP group, 20 cases in MSAP group and 40 cases in SAP group. Another 40 healthy volunteers who had physical examination in Tongchuan People's hospital during the same period were selected as the control group. The levels of serum LncRNA-HOTAIR and other inflammation related indexes, such as C-reaction protein （CRP）, procalcitonin （PCT）, amylase and lipase, were compared among the four groups, and the relationship between the serum LncRNA-HOTAIR level and the above inflammation related indexes was analyzed. Intend to evaluate the efficacy of serum LncRNA-HOTAIR in the diagnosis of acute pancreatitis. Results The relative expression of serum LncRNA-HOTAIR was significantly different in the four groups （P<0.05）, with the highest in the SAP group and the lowest in the control group. The levels of CRP, PCT, serum amylase and serum lipase in the SAP group were significantly higher than those in the other two groups （P<0.05）. After merging the data of patients in the MAP and SAP groups, it was found that the serum LncRNA-HOTAIR level of patients with acute pancreatitis was positively correlated with CRP （r=0.231, P=0.001） and PCT （r=0.192, P=0.003）, but was not significantly correlated with serum amylase and lipase. Receiver operating characteristic （ROC） curve analysis showed that when the relative expression of serum LncRNA-HOTAIR was >1.292, the sensitivity and specificity of the diagnosis of acute pancreatitis were 0.750 and 0.725, and the area under curve （AUC） was 0.783. ROC curve was used to analyze the diagnostic efficacy of serum LncRNA-HOTAIR in severe acute pancreatitis. It was found that when the relative expression of LncRNA-HOTAIR was >1.590, its sensitivity was 0.606, specificity was 0.936, and AUC was 0.837. Conclusions Serum LncRNA-HOTAIR levels were significantly elevated in patients with acute pancreatitis, and were positively correlated with the severity of the infection. In addition, serum LncRNA-HOTAIR has certain value in the diagnosis of acute pancreatitis, especially severe acute pancreatitis, and can further distinguish the severity of acute pancreatitis.