For thousands of years, natural products have played an important role throughout the world in treatment and prevention of human diseases. Objective: the main aim of this study was to evaluate the cytotoxic properties and anticancer effects of C.mas L. total extract as well as several fractions from the leaves. The total phenolics, flavonoids, and condensed tannins content of these extracts were also determined to obtain further information on the correlation between the contents of phenolic compounds and cytotoxicity effects as well as the leaf developmental stages. Materials and methods: Cytotoxicity activity was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method against human cancer and normal cell lines. The total phenolics, flavonoids, and condensed tannins were determined by Folin-Ciocalteu, aluminum chloride and butanol-HCl colorimetric methods. Results: The IC(50) values of young leaf hydro-alcoholic extract on MCF7,HepG2,MKN and CHO cells after 48h obtained to be 58.4, 78, 97.3 and 171.2 µg/mL, respectively. However, the IC (50) values for mature leaf extract were noted to be 94.2, 124, 147.1 and 258 µg/mL, respectively. The methanol fraction (IC50 values 30.1-71.1 μg/mL) from C. mas leaves showed more inhibitory activity than other. The colorimetric methods showed the amount of total phenolics, flavonoids and condensed tannins in young leaf more than mature leaf extracts. Discussion and conclusion: young leaf exhibited the highest values of cytotoxic activity than mature leaf. also young leaf had higher total phenol, flavonoid and condensed tannins content than mature leaf. This study suggests that which may be due to the presence of polyphenols in the leaf extracts.