Abstract: Objective To investigate the levels of osteopontin (OPN), interleukin-18 (IL-18) and interferon-gamma (IFN-γ) in sputum supernatant and serum in patients with pulmonary tuberculosis and its clinical significance. Methods Totally 96 patients with untreated pulmonary tuberculosis in our hospital and 84 normal controls were selected. Enzyme-linked immunosorbent assay (ELISA) was used to assay the levels of OPN, IL-18 and IFN-γ in sputum supernatant and serum samples. Results The levels of OPN, IL-18 and IFN-γ in serum in patients with pulmonary tuberculosis were increased significantly than those in control group, and the levels of OPN, IL-18 and IFN-γ in sputum supernatant were obviously higher than those control group. The levels of OPN, IL-18 and IFN-γ in sputum supernatant were increased with increasing of the amount of bacteria in sputum, but without statistically significant (P>0.05). Conclusion The levels of OPN, IL-18 and IFN-γ in sputum supernatant and serum in patients with pulmonary tuberculosis are increased significantly. Immune responses in pulmonary lesions of patients with pulmonary tuberculosis are much more strongly than systemic inflammatory response, and produce more inflammatory cytokines.