The anti-tumor effects of catechins and gallic acid(GA)in-vitro was investigated in this paper. Fluo-3AM, Calcium-AM(Ca-AM), 2′, 7′-dichlorofluorescein-diacetate(DCFH-DA), 4′, 6-diamidino-2- phenylindole(DAPI) and Ca-AM plus colbat were used to characterize intracellular calcium, labile iron pool(LIP), reactive oxygen species(ROS), nuclei morphology and mitochondrial permeability transition pore(mPTP) opening, respectively. High performance liquid chromatography(HPLC) was used to quantitate catechins and GA in the cultural medium. The results indicated that each of them showed dose response inhibition of cell growth, provoking nuclei condensation, intracellular calcium elevation, mPTP opening, LIP reduction, and cytochrome c(Cyt-C) to release into cytosol. The caspase inhibitors, 2-aminoethoxydiphenol borate(APB) or Fe3+ could inhibit lethal effects of GA and(-)-epigallocatechin(EGC), but failed to affect(-)-epigallocatechin gallate(EGCG) and(-)-epicatechin gallate(ECG). Level of ROS presented negative growth while their concentration decreased in the medium. In conclusion, our findings suggest that viability of RKO decreased because of their good correlation with elevation of calcium and loss of LIP and ROS in cytosol. Fluo-3AM, Calcium-AM (Ca-AM), 2 ’, 7’-dichlorofluorescein-diacetate (DCFH-DA), Anti-tumor effects of catechins and gallic acid (GA) 4 ’, 6-diamidino-2-phenylindole (DAPI) and Ca-AM plus colbat were used to characterize intracellular calcium, labile iron pool (LIP), reactive oxygen species (ROS), nuclei morphology and mitochondrial permeability transition pore (mPTP) opening, respectively. High performance liquid chromatography (HPLC) was used to quantitate catechins and GA in the cultural medium. The results indicating that each showed dose response inhibition of cell growth, provoking nuclei condensation, intracellular calcium elevation, mPTP opening, LIP reduction and cytochrome c (Cyt-C) to release into cytosol. The caspase inhibitors, 2-aminoethoxydiphenol borate (APB) or Fe3 + could inhibit lethal effects of GA and (-) - epigallocatechin (EGC) ) -epigallocatechin gallate (EGCG) and (-) - epicatechin gallate (ECG). Level of ROS result negative growth while their concentration decreased in the medium. In conclusion, our findings suggest that viability of RKO decreased because of their good correlation with elevation of calcium and loss of LIP and ROS in cytosol.