Abstract: Objective To analyze correlations between prognosis and serum carcinoembryonic antigen(CEA), lactate dehydrogenase(LHD), thyroid transcription factor-1(TTF-1)levels in patients with advanced lung adenocarcinoma undergoing chemotherapy. Methods A total of 62 patients with advanced lung adenocarcinoma undergoing chemotherapy were selected as research objects, their serum CEA, LHD, TTF-1 levels were detected, the relationships between serum CEA, LHD, TTF-1 levels and prognosis in patients with advanced lung adenocarcinoma undergoing chemotherapy were analyzed, and the conditions of survival and death of patients within 2 years of follow-up were explored. Results The serum CEA, LHD, and TTF-1 levels of the death group were higher than those of the survival group, and the differences were statistically significant(P<0.05). Logistic regression analysis showed that higher levels of serum CEA, LHD, and TTF-1 might be risk factors leading to death in patients with advanced lung adenocarcinoma undergoing chemotherapy(OR>1, P<0.01). The results showed that area under the curve(AUC)of the prognosis predicted by the levels of serum CEA, LHD, TTF-1 in advanced lung adenocarcinoma patients was above 0.7, which indicated that all the three indicators were of great value in predicting the disease. Conclusion Serum CEA, LHD, and TTF-1 may be involved in the occurrence and development of advanced lung adenocarcinoma, and are closely related to the prognosis of chemotherapy patients. Clinically, the prognosis of patients with advanced lung adenocarcinoma undergoing chemotherapy can be assessed by detecting serum CEA, LHD, and TTF-1 levels.