Sixty-two medical records of patients with coal workers' pneumoconiosis who died in hospital as coal workers' pneumoconiosis were analyzed for study of the relationship between forced expiratory volume in one second(FEV1) and life expectancy in coal workers' pneumoconiosis. In the group who died of asphyxia from hemoptysis, life expectancy were well fitted with FEV1 (p<0.05). But others were not well fitted to simple linear regression equation. The prevalence of ECG sign of cor pulmonale was more in the group of cardiorespiratory failure than asphyxia group. So, in the case of far advanced cor pulmonale, it was difficult to predict life expectancy by simple linear regression equation.