Abstract: Objective To investigate the relationship between procalcitonin (PCT), serum D-dimer and lung cancer. Methods A total of 166 patients with lung cancer in the last two years and 166 concurrent healthy people or patients without lung diseases were selected. Spearman rank correlation, dose-response relationship of Logistic regression and interaction effect were used to study the correlations between PCT, D-dimer and lung cancer. Results The age, PCT, carcinoembryonic antigen (CEA) and D-dimer were correlated with lung cancer (r_s=0.289, 0.262, 0.387 and 0.161). Age (≥ 60 years) (OR=2.53, 95% CI:1.28-5.00, P=0.008), PCT abnormalities (OR=2.10, 95% CI:1.07-4.14, P=0.032), CEA abnormalities (OR=11.68, 95% CI:4.57-29.82, P=0.001) and D-dimer abnormalities (OR=1.43, 95% CI:1.15-1.68, P=0.001) were influencing factors of lung cancer. With the increasing of PCT and D-dimer levels, the risk of lung cancer were increasing, which showed a positive dose-response relationship (all P<0.05). PCT and D-dimer had a positive additive model interaction with lung cancer, and at the same time increased the risk of lung cancer (interaction index=2.16, 95% CI:1.08 -5.43; interaction the role of excess relative risk=1.29, 95% CI 0.68-2.71; interaction attribution ratio=0.75, 95% CI:0.37-1.42). Conclusions High PCT and D-dimer are risk factors of lung cancer, and there is a significant dose-response relationship between them. Meanwhile,there is a positive additive interaction effect between PCT and D-dimer in an additive model,the risk of lung cancer will increase significantly when both of them are at an abnormal high level.