Abstract: Objective To investigate the clinical significance of plasma levels of hypersensitive C-reactive protein (hs-CRP), fibriogen and D-dimmer (D-DI) in patients with connective tissue disease (CTD)-related interstitial lung disease (CTD-ILD). Methods Sixty-nine patients with interstitial lung disease admitted in Zhujiang Hospital between January, 2010 and April, 2016, including 29 with CTD-ILD and 40 with non-CTD-ILD were analyzed for plasma levels of hs-CRP, fibriogen and D-DI, with 25 healthy subjects as the control group. Results The plasma level of hs-CRP, fibriogen and D-DI in patients with CTD-ILD and non-CTD-ILD were all significantly higher than those in the control group. The patients with CTD-ILD had a significantly higher hs-CRP level than those with non-CTD-ILD, but the levels of fibriogen and D-DI were comparable between the two groups. Correlation analysis indicated that Hs-CRP level was positively correlated with the levels of D-DI (r=0.539, P< 0.01) and fibrinogen (r=0.534, P<0.01). Conclusion Hs-CRP, fibriogen and D-DI levels show an important value in clinical diagnosis of CTD, and an obvious elevation of hs-CRP is correlated with the CTD.