It is known that lymphatic capillaries surrounding tumors play a functional important role in invasion and metastasis of the cancer. In this study, absorbing substances from tissues by lymphatic capillaries around the tumor was evaluated in VX2 tongue carcinoma using horseradish peroxidase (HRP) as a tracer. Subjects were rabbits which were 7 and 14 days after VX2 carcinoma transplantation into their tongues. HRP was infused under the mucosa of the tongue at the site of tumor transplantation, and specimens for transmission electron microscopy were prepared. HRP was absorbed by lymphatic capillary endothelial cells from surrounding tissues through intercellular endothelial spaces and pinocytotic vesicles. More vesicles were observed in 7 and l4 days after transplantation of VX2 carcinoma than in the control group. Also, the amount of HRP transferred from the abluminal side of endothelial cells through intercellular endothelial spaces and accumulated on the cell membrane of the luminal side increased after transplantation. The number of pinocytotic vesicles increased in endothelial cells in the transplanted groups as compared with the control group, and the length of adhesion apparatus in intercellular endothelial spaces was reduced. These results suggested that the transport of substances especially via intercellular endothelial spaces and vesicles increased with progression of tumor in lymphatic capillary surrounding tumor.