Abstract: Adhesive Interaction between cells and the extracellular matrix is a essential condition of the tumor metastasis. There are many celladherent proteins in normal human plasma, such as fibronectin （FN）, laminin （LN）, Vitronectin, collagen and etc. It is the purpose of this article to study the biological properties of the protein enzymolysic product （EP） from normal human plasma （NHP） and the inhibition of the experimental tumor metastasis of the murine FC gastrocarcinoma cells with the enzymolysic products （EP） of NHP. The enzymolysic product of the NHP was preparated with-chymotrypsin and pepsin combinding digestion: The enzymotysic product of the NHP has been studied with MGc80-3 cells （human gastrocarcinoma cell line） and FC cells （615-murine gastrocarcinoma cell line）. The NHP showed a noted character of cells attachment, while the NHP-EP showed a high capacity of inhibition of cells attachement with does dependent, specific, noncytoxic, competitive and reversible characters. Introveinous coinjection of NHP-EP with FC mourine gastrocarcinoma cells remarkablly inhibited the formation of lung colonies in 615-mice. 83% of the lung colonies were inhibited and the median survival time prolonged to 35 days comparing with the controls of 19 days. This study shows that, the NHP-EP has potential efficacy for inhibition of hematogenous metartasis with a mechanism of action involving interference with tumor cell adhesion to the target organ. In the future, NHP-EP may be potentially useful as an adjufant to chemotherapy, radiotherapy or immunotherapy or to provent seeding of metastatic cells after surgical removal of a primary tumor.