Objective　To study the occupational lung cancer among Yunnan tin miners during 1992-1997 by sputum cytology. Methods　The data of cases and occupational high-risk population for lung cancer among tin miners (Age≥40 years old and worked underground and／or at smeltery≥10 years) were analyzed. Results　There were 339 patients with lung cancer determined during six years, in which squamous cell carcinoma was 56.34％. The average incidence age was 65.78 years of age. The average positive rate to sputum cytology examination was 32.74％. The accuracy, specificity and sensitivity to sputum cytology examination were 99.35％, 99.81％ and 39.22％ respectively. The positive predictive value of sputum cytology examination was 62.01％, which was significantly higher than X-ray (33.05％)(P＜0.01). There were 48 recessive lung cancer cases and 12 suspicious recessive lung cancer cases found with sputum cytology during the six years. Conclusion　The sputum cytology examination is still one of the most effective methods for lung cancer screening among occupational high-risk population. The occupational high-risk population should be defined again (the tin miners' age≥50 years old and had worked underground and／or at smeltery≥10 years).