Backgrounds: Bintangor leaf (Calophyllum soulattri Burm.f) has been used by public for various medical treatments including to treated inflamed eyes and gout pain. Objectives: This research aimed to determine the cytotoxic effect of ethanol extract and fraction of Calophyllum soulattri Burm. f leaf toward T₄₇D breast cell cancer. Material and Methods: This cytotoxic test used T₄₇D breast cell cancer by using 3-[4,5-dimethylthiazol-2yl] -2,5-diphenyltetrazolium bromide (MTT) test method and read absorbance by ELISA Reader. The principle of this method was the presence of tetrazolium salts by the reductase system in the mitochondria of living cells formed purple formazan crystals. The used parameter was the value of IC₅₀. Result: The result showed that ethanol extract, n-hexane fraction, ethyl acetate fraction, and butanol fraction did not have a cytotoxic effect toward T₄₇D breast cell cancer. The values of IC₅₀ respectively are585.31 µg/ml; 409.33 µg/ml; 534.08 µg/ml; and 563.22 µg/ml. Conclusion: Ethanol extract and Calophyllum soulattri Burm.f leaf fraction did not have a cytotoxic effect on T₄₇D breast cancer cells.