Objective To study the effect of lung cancer prevention in Baoji city, one of the cities with high lung cancer morbidity in China. Methods To investigate the mortality of lung cancer from 1992 to 1996 in Baoji and compare it with the data of Baoji in 1970s and the current data in whole China. Information of lung cancer patients was collected from the Malignant Tumour Monitoring Station in Baoji. To investigate by sampling survey the status of smoking of Baoji population based on the principle of clustering random sampling. Information about air pollution in 1980s and 1990s was obtained from the Environmental Monitoring Station in Baoji. Results Comparing with 1970s, the crude mortality rates of lung cancer in Baoji in 1992~1996 increased both in males and females,but the range was narrower than that in whole China.Ajusted mortality rates of lung cancer didnt change in females but decreased in males. However, either crude or adjusted mortality rate was lower than the average level of the whole country. The status of air pollution has been improved dramatically since the early 1980s in Baoji. So far, except total suspended particles (TSP), NOx and SO 2 levels have reached the Criteria of Air Quality of China. But the smoking rate was still higher. Conclusion The prevention of lung cancer in Baoji is effective, but the role of measures needs further study. Baoji should not be considered as a city with high lung cancer morbidity in our country at present. Objective To study the effect of lung cancer prevention in Baoji city, one of the cities with high lung cancer morbidity in China. Methods To investigate the mortality of lung cancer from 1992 to 1996 in Baoji and compare it with the data of Baoji in 1970s and The current data in whole China. Information of lung cancer patients was collected from the Malignant Tumour Monitoring Station in Baoji. To investigate by sampling survey the status of smoking of Baoji population based on the principle of clustering random sampling. Information about air pollution in 1980s And 1990s was obtained from the Environmental Monitoring Station in Baoji. Results Comparing with 1970s, the crude mortality rates of lung cancer in Baoji in 1992~1996 increased both in males and females,but the range was narrower than that in whole China.Ajusted mortality. Rates of lung cancer didnt change in females but decreased in males. but, either crude or adjusted mortality rate was lower than the average le Vel of the whole country. The status of air pollution has been improved switch since the early 1980s in Baoji. So far, except total suspended particles (TSP), NOx and SO 2 levels have reached the Criteria of Air Quality of China. But the The smoking rate was still higher. Conclusion The prevention of lung cancer in Baoji is effective, but the role of measures needs further study. Baoji should not be considered as a city with high lung cancer morbidity in our country at present.