Antioxidant enzyme activity protect body from free radicals and its effect in human life. However, it can be resist for the some drugs such as anti-tumor, chemotherapy drugs and etc. In this study, antioxidant effect of Ganoderma Lucidum which is known as Reishi and, its extract that is prepared by using 0.1 mg/mL, was analyzed by measuring its total phenolic and total flavonoid contents, protein content and lastly measuring the effect of mushroom extract on the activity of the antioxidant enzymes; glutathione-S-transferase, superoxide dismutase and protein tyrosine kinase. The mushroom extract was prepared in by using water and its total phenolic and flavonoid contents of extract was measured and they were used in the further analysis. The activated effect of reishi was observed on these three enzymes and due to these activities; reishi is not available to use with cancer drugs as a supplement or alternative medicine. Also, observed that reishi can be used as food supplement and etc. Finally, cytotoxicity test was performed with K-562 cells and observed that reishi extract was increased the viability of cells.