experiences 6 5 kg dried roots of reevesia formosana were cut into slices then the slices were extracted by 30 l methanol for three times in the room temperature after eliminating the solvent the 150 g methanolic extractive was partitioned into an etoac fraction and a water fraction by etoac and h 2 o and 45 g etoac fraction and 100 g water fraction were acquired these two fractions were had active examination and results showed that the methanolic extractive had been shown cytotoxicity against mcf 7 nci h460 and hepg2 cancer cell lines the 45 g etoac fraction was subjected to a silicon column 70 230 sieve 1 5 kg and a concentration gradient of n hexane etoac was applied on elution to acquire 1 u02dc 12 fractions and at last methanol was used to elute to form 13 fractions totally the fractions 9 u02dc 13 had been shown cytotoxicity against mcf 7 nci h460 and hepg2 cancer cell lines the fraction 10 which was subjected to passage over a sephadex lh 20 column eluting with 100 methanol to yield 13 fractions fractions 10 1 to 10 13 the fraction 10 3 0 87 g was separated over a rp c 18 column 20 40 u03bcm silicon eluting with a mixing solvent of the methanol water 3 2 and fractions 10 3 1 to 10 3 12 were obtained compound 1 460 mg was separated from the fraction 10 3 8 and a crystal mixture.