158 cases of pulmonary metastasis having satisfactory histological proof of the primary malignant tumor, the frequency and pattern of which were analysed by conventional radiological approaches at presbyterian Medical Center from Jan. 1978 to DEC. 1982, were evaluated radiologically. The results are as follows: 1. The frequency of pulmonary metastasis according to the promary 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 nck. 2. Pulmonary metastatic 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 tese type, nodular type was predominant. 3. The nodular type of pulmonary metastasis was classified into less than 10 nodules 56.4% (66/17) 10-50 nodules 25.6%(30/117), more than 50, 17.9% (21/117). 4. The size of nodule was 1-3cm 36.6% (43/117), 2-3cm 20.5% (24/117), less than 1cm 12.8% (15/117) and more than 5cm in 5.2% (1/117) of the cases. 5. Most cases of pulmonary metastasis involved both lung fields 69.6% (110/58). Others were right lung field only 17.7% (28/158), left lung only 12.7% (20/158) 6. The ages between 40 and 70 represented 79.8% (126/158) of the cases and the ratio of male and female was about 1.5:1.