NOVELTY - Tobacco stem is used in cultivating medicinal fungi Ganoderma lucidum by harvesting tobacco stem; crushing into powder; drying; subjecting into compost fermentation with lime water and urea; preparing G. lucidum culture medium raw materials comprising the fermented tobacco stem, wheat bran, sawdust, gypsum and lime; adding with water; uniformly mixing to obtain G. lucidum culture medium formulation (A); and placing the formulation (A) in a bag to utilize it in conducting G. lucidum artificial cultivation according to conventional cultivation method.    USE - Tobacco stem used in cultivating medicinal fungi G. lucidum (claimed).    ADVANTAGE - The use of tobacco stem in cultivating medicinal fungi G. lucidum enables the abundant waste tobacco stems to be developed comprehensively and turned into valuable material for the production of G. lucidum having high medicinal value, thus it does not only improve the additional value of tobacco planting but also widen the medicinal fungi G. lucidum planting method, save wood resources, increase farmer's income, and protect rural ecological environment. Further, it is environment-friendly and energy-saving, reduces waste emission, and has great development prospect.    DETAILED DESCRIPTION - Tobacco stem is used in cultivating medicinal fungi G. lucidum by (a) harvesting tobacco stem after collecting tobacco leaf; (b) crushing tobacco stem into powder with 2-5 mm particle diameter; (c) air drying or sun drying the tobacco stem powder to a moisture content of 20-35 % if it is used right away in the G. lucidum cultivation process, or 10-14 % if it has to be stored for a long time for later use; (d) adding the dried tobacco stem powder with 2 % of lime water and 0.1 % of urea, compost fermenting for 5 days, and turning the material for 1-2 times; (e) preparing G. lucidum culture medium raw materials comprising (wt.%) the fermented tobacco stem obtained step (d) (55-30), wheat bran (23), sawdust (45-20), gypsum (1) and lime (1); adding with water based on 1:1.2 material-to-water ratio; (f) uniformly mixing the materials to obtain G. lucidum culture medium formulation (A), and placing the formulation (A) in a bag to utilize it in conducting G. lucidum artificial cultivation according to conventional cultivation method.