The authors evaluated diagnostic value of non-invasive methods and other modalities in diagnosing primary lymphedema. We also evaluated the radiologic findings. Dirent(N=7) and indirect lymphangiograms(N=7), CTscan(N=4), and ultrasonogram(N=3) were performed on 14 patients with primary lymphedema of the lower extremities.Also, comparison CT scan and ultrasonogram were perfromed on 50 normal volunteers. The results were as follows: 1.Lymphedma was classified as praecox and tarda according to the onset of symptoms. Their percentages were 71.4% and28.6% respectively. 2. Lymphangiogram classification showed the following in the order of frequency;hypoplasia(78.6%), aplasia(14.3%) and hyperplasia(7.1%) 3. The mean midtibial subcutaneous fat ratio of thelymphedema patients was 37.73% on the CT scan which was greater than that of the normal subjects(20.05±14.04%).4. On the ultrasonogram, mean premidtibial dermis and subcutaneous fat thickness of the lymphedema patients was6.3mm, which was greater than that of the normal subjects(2.9±2.4mm). 5. In conclusion, CT scan and ultrasonographic examination were helpful as a non-invasive method for evaluating the follow-up of patients treated for lymphedema.