Abstract: Objective In order to screening the phage-display random 12 peptide specific to the lung cancer and explore early diagnosis,differential diagnosis and clinical treatment for lung cancer.Methods We sdected the serum of lung cancer patient,benign tumor and normal tumor,which was 35 case respectirely,Using the phage random 12 peptide library screening(the lung cancer specific phage clones),we pooled these serum as a screening ligand.Then,the Dot-ELISA is used to identify the lung cancer specific phage clones reactive to sera of the lung cancer patients and normal controls individually.Results Total 12 of the phage-display random 12 peptide are obtained by phage peptide library screening and the Dot-ELISA identification.Mix of positive cloning respectively with the 12 cases of lung cancer patients and 12 cases of normal serum reaction and 12 cases of lung cancer patients serum all positive,normal serum all negative,sensitivity of 100% and specificity of 100%.Conclusion Lung cancer-specific peptides were screened by phage random peptide library maybe used to diagnosis the lung cancer,and implementing early detection and early intervention has important theoretical significance and application value of lung cancer.