Abstract: Tumor lymphatic metastasis is one of the most sophisticated medical problems with undetermined etiology and high mortality，demanding prompt solutions. Although various hypotheses have been introduced previously and researches have focused on the tumor cells themselves，none of which can fully elucidate the pathogenesis of lymphatic metastasis. Recent researches have shown the interaction between tumor cells and other cells in the tumor microenvironment. Lymphatic endothelial cell （LEC） is an important one in the tumor microenvironment，closely relating with tumor lymphatic metastasis. Therefore，further study on interaction of LEC and tumor cells may bring a new dawn for the etiology of lymphatic metastasis as well as traditional anti-cancer treatment.

Key words: Lymphocytes, tumor-infiltrating, Endothelial cells, Endothelial growth factors, Lymphangiogenesis, Lymphatic metastasis