Sonchus tenerrimusis known as slender sow thistle and belongs to the family Asteraceae. It is native to the Mediterranean regions. The seeds and leaves of the plant were subjected to phytochemical and biological investigations. Protein hydrolysate of the seeds of S. tenerrimus was analyzed using HPLC resulting the identification of 14 amino (29.15 mg/ 100 g seed). Glutamic acid was the major constituent in the plants. GC/MS analysis GLC/ MS analysis of unsaponifiable matters of S. tenerrimus revealed the identification of 36 compounds and phytolis the major constituent while ethyl acetate fraction contains hyperoside as a major product. All plant fractions showed significant antioxidant and anticancer activities except unsaponifiable fraction showed weak activities.