Objective:To explore the relationship between the expression of angiopoietin 1 (ANGPT1) and Smadhomolog 9 (Smad9) genes in cancer tissues and tumor metastasis, invasion behavior and prognosis in patients with lung adenocarcinoma.Methods:Sixty patients with lung adenocarcinoma in Chengwu Hospital Affiliated to Shandong First Medical University from October 2018 to December 2019 were selected as the research objects. The expressions of ANGPT1 and Smad9 mRNA in cancer tissues and adjacent tissues were compared, as well as the expressions of ANGPT1 and Smad9 mRNA in cancer tissues of patients with different tumor metastasis and invasion behaviors. The relationship between ANGPT1 and Smad9 mRNA expression and tumor metastasis and invasion behavior of lung adenocarcinoma were analyzed, and the 1-year survival rate of patients with lung adenocarcinoma was calculated. The 1-year survival rate of patients with different ANGPT1 and SMAD9 mRNA expression levels were compared.Results:The relative expression of ANGPT1 mRNA and Smad9 mRNA in cancer tissues were lower than those in adjacent tissues: 2.45 ± 0.26 vs. 11.18 ± 0.93, 4.23 ± 0.31 vs. 7.58 ± 0.65, the differences were statistically significant ( P<0.05). There were significant differences in the relative gene expression of ANGPT1 and Smad9 mRNA in different clinical stages, tumor diameter, degree of differentiation, lymph node metastasis and pleural invasion ( P<0.05). Spearman correlation analysis showed that the expression of ANGPT1 and Smad9 mRNA were negatively correlated with clinical stage, tumor diameter, lymph node metastasis and pleural invasion ( r = - 0.517, - 0.539, - 0.606, - 0.679, P<0.05), and positively correlated with the degree of differentiation ( r = 0.628, P<0.05). The 1-year survival rate of 58 patients was 72.41%. Kaplan-Meier curve analysis showed that the 1-year survival rate of patients with low expression of ANGPT1 and Smad9 mRNA in cancer tissues were were lower than those in patients with high expression ( P<0.05). Conclusions:Down-regulation of ANGPT1 and Smad9 genes in cancer tissues will accelerate the metastasis and invasion behavior of lung adenocarcinoma. Up-regulating the expression of both genes can be a potential way to improve survival.