Abstract: Objective To understand the industrial distribution of welding operation and the severity of occupational diseases caused by exposure to welding fumes. Methods The records of welding operation in the data bank of Shanghai Reporting System of Occupational Hazards were abstracted and analyzed. Results A total of 3 547 enterprises had welding fumes in their companies and 67 030 workers were exposed to such hazards. The enterprises were distributed in the industries of metal products,machinery,automobile,structural metal products,the ship,manufacturing,and so on. A total of 83 cases of welders' pneumoconiosis were diagnosed in recent 3 years. Conclusion Welding operation in Shanghai is common and distributed in various industries and there are large number of workers exposed to welding fumes. The health problem caused by such occupational hazard is apparent and we should pay more attention to this.