Silybum marianum(milk thistle),an annual or biennial herbaceous plant,has been used to treat liver disease for 2000 years.An efficient system for micropropagation from leaf explants of wild-grown S.marianumwas successfully established and the genetic fidelity of micropropagated plants was assessed using random amplified polymorphic DNA(RAPD).The highest frequency(100%)of callus induction was obtained from explants cultivated for 4 weeks on Murashige and Skoog(MS)medium supplemented with 1.5 mg/l benzylaminopurine(BA)and 2.0 mg/l naphthylacetic acid(NAA).