The analysis of 35 cases who revealed lymphatic obstruction and lymphatic stasis due to malignant metastasis on bipedal lymphangiography, to evaluate the various radiological patterns of lymphatic obstruction and pathophysiologic mechanisms due to lymphatic obstruction, from Oct. 1975 to Apr. 1982 at YUMC Hospital was undertaken and the following results were obtained. 1. Of these, 12 had complete lymphatic obstruction and 22 partial lymphatic obstruction on lymphangiography. There was lymphatic collateral circulation in 14, extravasation of contrast media in 12, lymphatic dilatation in 9, dermal backflow in 6, and only lymphatic stasis in 10. 2. According to the level or location of lymphatic obstruction, there were 17 at external iliac lymph nodes, 10 below the inguinal lymph nodes, and 8 above the common iliac lymph nodes. 3. Lymphatic collateral circulation was developed mainly by neoformation of subcutaneous lymphatics below the inguinal lymph nodes obstruction, collateral flow into the internal iliac lymphatics at external iliac lymph nodes obstruction, collateral flow int the mesenteric and mediastinal lymphatics above the common iliac lymph nodes obstruction. 4. Pulmonary oil embolism was developed in 12 of 175 (7%) in control group, but in 14 of 35 (40%) in lymphatic obstruction group. Finally, the dynamic eveluation of lymphatic flow in lymphangiogroaphy is more important than the morphologic evaluation of lymph nodes in advanced malignant disease.