The present invention relates to Saxatilin, a protein derived from the venom of a Korean snake, Agkistrodon saxatilis emelianov, a process for preparing Saxatilin, and pharmaceutical application of the same as anti-platelet aggregation agent and anti-tumor agent. The present inventors purified Saxatilin from the venom of Agkistrodon saxatilis emelianov, cloned its cDNA, and prepared recombinant Saxatilin by culturing a microorganism transformed with an expression vector containing the cDNA. Saxatilin effectively suppresses the platelet aggregation and angiogenesis of tumor cells, which makes possible its practical application as an active ingredient of anti-platelet agent and anti-tumor agent.