The present study aims to determine the nutrients and nutraceuticals content and in vitro biological activities of reishi mushroom (Ganoderma lucidum) fruiting bodies. Data of the nutrients composition of Ganoderma lucidum powder indicated that crude fiber and carbohydrates were the most largest compounds (50.19 and 37.33%, respectively) followed by total protein (8.54 %), ash (2.03 %) and crude fat (1.91%.). Also, Ganoderma lucidum powder is rich in different estimated elements (K, P, Ca, Mg, Na, Fe, Zn, Mn, Cu and Se) and vitamins (A, B1, B2, B3, B6, zb9, C and E). Furthermore, nutraceuticals (bioactive compounds) content of Ganoderma lucidum powder indicated that terpenoids were the most largest compound (2541 mg linalol.100 g-1 ) followed by polysaccharides (1635 mg starch equivalent. 100 g-1 ), phenolics (572.67 mg gallic acid equivalent. 100g-1 ), triterpenoids (495 mg ursolic acid.100 g-1 ), Flavonoids (279.34 mg catechin.100 g-1 ), and Lycopene (253.11 µg.100 g -1 ). The different extracts of Ganoderma lucidum samples particularly ethanolic and methanolic also recorded several very high biological activities which include antioxidant activity, scavenging of free radicals, inhibition of low density lipoprotein oxidation (anti-atherosclerotic) and as antibacterial and antifungal. Such important biological effects could play important roles in strategies to combat/ prevent/treat many diseases, especially those for which oxidative stress is one of the mechanisms for its occurrence i.e. diabetes, cancer, atherosclerosis, cardiovascular diseases etc. Therefore, the present study recommended like of that Ganoderma lucidum fruiting bodies powder and/or extracts to be included in our daily diets, drinks, food supplementation and pharmacological formulae