Cancer has become the major factor causing death in Taiwan. Although brain tumor take a few ratio in cancer, the current therapy shown not effect well. In previous studies, EGCG will promote cancer cells to go apoptosis after treatment with EGCG. But the mechanism in brain tumor is unknown. So, we use EGCG from green tea extract to investigate cell death of human brain tumor cell lines GBM8401, U87MG and U251. The metabolic rates of GBM8401, U87 and U251 are decrease with EGCG treatment, and it is significant in GBM8401. We also examine some genes and proteins related apoptosis by RT-PCR and Western blotting. The accumulation of p21, p27 and p53 are increasing with concentration and time course treatments. EGCG can inhibit the ability of brain tumor to form foci in anchorage-independent growth assay. Our data show that EGCG can inhibit brain tumor cell lines GBM8401, U87 and U251. It is validated that EGCG has the potential of cancer therapy and prevention.