Abstract: Objective To study the relationship between pulmonary function and plasma fibrinogen （PF） in patients with coronary heart disease （CHD）， and investigate the effects of CHD on pulmonary function. Methods Clinical data about 220 CHD patients（163 males and 57 females， age range from 26 to 83 years） admitted to our department from August 2013 to October 2014 were collected. Venous blood samples were taken for laboratory testing. Pulmonary function was measured by our pulmonary function technicians. Patients were divided into groups by sex and pulmonary function. The relationship of PF level and pulmonary function was analyzed. Results In male CHD patients， PF was negatively related to forced expiratory volume in one second （FEV1%）， forced vital capacity （FVC%）， vital capacity （VC%）， diffusion capacity of the lung for carbon monoxide （DLCO%）. The DLCO% and PF in abnormal lung function group showed significant difference （P=0.011）. Conclusion In male CHD patients， PF level is significantly related to pulmonary function and may be a predictor of pulmonary dysfunction. Rising of PF level may result in reduction of lung diffusing capacity.