Plant polyphenols have drawn increasing attention due to their potent antioxidant properties and their marked effects in the prevention of various oxidative stress associated diseases. In this work, thyme (Thymus vulgaris L.) leave water extract (TLE) was investigated for total phenolic compound total flavonoid, and the cytotoxic effect of studied extracts against human cell lines HCT 116 and PC3 occurred.The results showed that the extract had high content of these parameters. Scavenging activity of thyme (Thymus vulgaris L.) leaves water extract against DPPH and β-Carotene free radicals were determined and the results showed that TLE were characterized by a high content of antioxidants compound.Data showed that water extract of thyme (TLE) possessed good potent inhibitory activities against HCT 116, and PC3 cell lines. The anticancer effect of water extract of thyme (TLE) encourages the use of it as protective agents for normal cell line.