Silybum marianum (Milk thistle), a part of the Asteraceae family, is a tall herb with huge prickly white- veined green leaves as well as a reddish-purple flower that split ends in sharp spines. Many of the phytoconstituents were shown such as silybin A, silybin B, isosilybin A, isosilybin B, silychristin, silydianin, kaempferol, taxifolin and quercetin. The sylimarin microscopic characteristic with its morphological characteristic were also known. The plant is entirely used as anti-diabetic, hepatoprotective,  hypocholesterolaemic, anti-hypertensive, , anti-cancer, and as an anti-oxidant.. The plant is also serves as a galactagogue and used in the treatment of uterine disorders. These plant showing the synergistic effect with glyrrihizin and cancer drug. This review paper focuses mainly on phytochemistry and pharmacological activities as well as dosage regimen and its pharmacokinetics of the well-known plant milk thistle.