Objective To study on the correlation of CT features and tumor markers and on the diagnostic value of the combination both in detection for central pulmonary SCLS and squamous carcinoma. Methods 52 cases central pulmonary SCLS and squamous carcinoma confirmed by pathology received CT scan and the test of tumor markers which included CA125、CEA、CYFRA21-1、NSE、ProGRP、SCC.CT features were analysed comparatively with serum tumor markers test. Results There were significance between tumor features,density,enhancement, bronchial truncation,obstructive atelectasis,lymph node metastases(p＜0.05).There were difference between CYFRA21- 1,NSE,proGRP,SCC.CYFRA21-1,SCC of squamous carcinoma were higher than SCLC.NSE,proGRP of SCLC were higher than squamous carcinoma.The combination of CT features and test of tumor markers were better than the single one in detecting lung cancer.There were significance between CYFRA21-1 and density and enhancement(p ＜0.05).There were significance between CEA and lymph node metastases(p＜0.05). Conclusion Combination of CT features and tumor markers could improve the accuracy rate in diagnosing lung cancer. Density and enhancement have certain correlation with CYFRA21-1.Lymph node metastases have certain correlation with CEA.