OBJECTIVE To investigate the possible influencing factors of pulmonary dysfunction in coal worker's pneumoconiosis (CWP). METHODS A total of 141 patients with CWP and 200 control miners with similar exposure histories but without apparent pulmonary disease or inflammation were interviewed with the detailed questionnaires (including histories of coal dust-exposure, smoking habits, alcohol consumption, protective mask uses, et al). Lung function examinations were performed at the same time. Predicted formula of lung function index were established by the local healthy residents characters and the pulmonary dysfunction was classified by the ratios between tested and predicted values. RESULTS All parameters of lung function were significantly lower in CWP cases when compared with that of control miners and the healthy controls (P < 0.05). The main types of pulmonary dysfunction were restrictive and mixed ventilation disorders in CWP patients. The factors such as the category of CWP, the mask worn, the smoking quantity and exposure to coal mine dust were included in the unconditional logistic regression model. CONCLUSIONS The category of CWP, the usage of mask, the smoking and long duration exposure to coal mine dust may be the main possible influencing factors of pulmonary dysfunction of CWP. Influencing factor analyses were given to inform choice of pertinence preventive measures.