[en] Objective: To analyze the related factors in calcification of lung cancer and its significance. Methods: One hundred and ninety-four cases of peripheral carcinoma of the lung demonstrated by CT from Nov. 1991 to Nov. 1998 were collected. Of them, 148 cases were males and 46 were females, with the age ranging from 24 to 88 years (the average age was 60 years). There were 24 cases (12.4%) with calcification. Results: (1) The incidence of tumor calcification did not correlate with pathological type. (2) The incidence of tumor calcification in large lung cancers was higher than that of the small ones. (3) The incidence of tumor calcification in older patients was higher than that in younger ones. (4) The incidence of tumor calcification in lung or mediastinal lymph nodes with calcification is higher than that in those without calcification. (5) Although the incidence of tumor calcification in the predilection sites for tuberculosis (apical posterior segment of upper lobe and dorsal segment of lower lobe) is slightly higher than that in not predilection sites, there was no difference in statistical analysis (Mantel-Heanzel x² test, x² = 1.870, P = 0.171 > 0.05). Conclusion: In diagnosis of solid space-occupying lesions of lung, misdiagnosis may result if determination of benign or malignant changes is based only on presence or absence of calcification, and in order to make correct diagnosis, other signs of the lesions should also be considered