Abstract: Objective To study the expression of LIM domain 3(FHL3) in lung cancer and its possible mechanism. Methods Seventy fresh lung cancer and normal lung tissue samples were collected during operation in our department.Rabbit anti-human FHL3 antibody was detected by Western blotting with immunohistochemical staining.Expressions of FHL3 in lung cancer and normal lung tissues were compared.Lung cancer cells and human embryonic lung cells were cultured and analyzed by Western blotting. Results The expression of FHL3 in lung cancer tissue was correlated with the gender of patients,pathologic type and TNM classification of lung cancer but not with the age of patients,differentiation and size of lung cancer.The expression level of FHL3 was significantly higher in adenocarcinoma tissue than in normal lung tissue.FHL3 was over-expressed in 2 highly malignant cell lines,Calu-3 and H1299. Conclusion FHL3 expression is up-regulated in lung adenocarcinoma tissue and may play a role in transcription regulation of lung adenocarcinoma.