158 cases of pulmonary metastasis having satisfactory histological proof of the primary malignant tumor, thefrequency and pattern of which were analysed by conventional radiologically. The results are as follows: 1. Thefrequency of pulomonary metastasis according to the primary sites was 24%(38/158) hepatobiliary system,19.6%(31/158) gastrointestinal tract, 18.9%(30/158) uterine cervix and 12%(13/158) head and neck. 2. Pulmonarymetastatic pattern showed nodular type 74% (117/158), granular type 10.1%(16/158), streaky type 9.5%(15/158),hilar enlargement 3.8%(6/158), patchy type 1.9% (3/158) and others 0.6%(1/158). Of all these type, nodular typewas predominant. 3. The nodular type of pulmonary metastasis was classified into less than 10 nodules56.4%(66/17), 10-50 nodules 25.6%(30/117), more than 50, 17.9%(21/117), less than 1cm 12.8%(15/117) and more than5cm in 5.2%(1/117) of the cases. 4. The size of nodule was 1-3cm 36.6%(43/117), 2-3cm 20.5%(24/117), less than 1cm12.8%(15/117) and more than 5cm in 5.2%(1/117) of the cases. 5. Most cases of pulmonary metastasis involved bothlung fields 69.2%(110/58). Others were right lung field only 17.7% (28/158), left lung only 12.7%(20/158). 6. Theages between 40 and 70 represented 79.8%(126/158) of the cases and the raio of male and female was about 1.5:1.