Objective:To explore the role of a disintegrin-like and metalloproteinase with throm bospondin typeⅠmotifs-8(ADAMTS8) gene in lung adenocarcinoma and its mechanism.Methods:Selected lung adenocarcinoma data sets GSE75037 and GSE116959 and lung adenocarcinoma transcriptome data and clinical information from the TCGA database; useed R software to analyze differential genes in lung adenocarcinoma tissues, and performed GO enrichment analysis and KEGG signal pathway enrichment for differential genes set analysis; analyzed the expression of ADAMTS8 gene in lung adenocarcinoma and its correlation with patient survival and prognosis; CCK-8 experiment detects the effect of ADAMTS8 overexpression or knockdown on the proliferation of A549 cells; Western blot detected ADAMTS8 overexpression or knockdown effect on Wnt/β-catenin signaling pathway. Results:The combined analysis found that 395 genes were up-regulated in lung adenocarcinoma samples, and 716 genes were down-regulated; ADAMTS8 was under-expressed in lung adenocarcinoma tissues, and its expression level was related to tumor stage; low-expression of ADAMTS8 was associated with shorter survival time, poor prognosis, Cox regression analysis showed that ADAMTS8 can be used as an independent prognostic marker for patients with lung adenocarcinoma; CCK-8 results showed that overexpression of ADAMTS8 can inhibit the proliferation of A549 cells, knocking down ADAMTS8 can promote the proliferation of A549 cells ( P<0.05); Western blot results showed that after overexpression of ADAMTS8, the protein levels of β-catenin, cyclin D1 and c-Myc in cells were significantly reduced ( P<0.05), while knocking down ADAMTS8 could cause the protein levels of β-catenin, cyclin D1 and c-Myc in cells increased significantly ( P<0.05). Conclusions:ADAMTS8 is under-expressed in lung adenocarcinoma and can be used as an independent prognostic marker for patients. Overexpression of ADAMTS8 may inhibit the proliferation of lung adenocarcinoma cells by inhibiting the activity of Wnt/β-catenin signaling pathway.