NOVELTY - Mushroom culture substrate comprises broadleaf sawdust, wheat bran, rice bran, peat, corn flour and organic fermented material, where the organic fermented material is prepared by adding livestock stool, silkworm excrement, biogas, crop straw and 5-15% microbial inoculum, stacking mixture and fermenting mixture, and the microbial inoculum is prepared by mixing Candida utilis, Bacillus subtilis, B.mycoides, Streptococcus faecalis, Lactobacillus casei, Aspergillus niger, Humicola grisea, and culturing microbes.    USE - The mushroom culture substrate is useful for increasing disease resistance of edible fungus.    ADVANTAGE - The mushroom culture substrate is rich in organic matter.    DETAILED DESCRIPTION - Mushroom culture substrate comprises 8-15 pts. wt. broadleaf sawdust, 3-8 pts. wt. wheat bran, 3-8 pts. wt. rice bran, 1-3 pts. wt. peat, 1-3 pts. wt. corn flour and 3-8 pts. wt. organic fermented material, where the culture substrate has pH of 5-6 and water content of 60-70%, and the organic fermented material is prepared by adding livestock stool, silkworm excrement, biogas, crop straw and 5-15 wt.% microbial inoculum, stacking mixture and fermenting mixture for 15-25 days, and the microbial inoculum is prepared by mixing C.utilis, B.subtilis, B.mycoides, S.faecalis, L.casei, A.niger and H.grisea, and culturing microbes. An INDEPENDENT CLAIM is included for method of preparing mushroom culture substrate, which involves (a) adding 2-4 pts. wt. livestock stool, 0.5-1.5 pts. wt. silkworm excrement, 0.5- 1.5 pts. wt. biogas and 1-3 pts. wt. crop straw, where crop straw is cut into 1-3 cm using guillotine, and uniformly mixing mixture, (b) preparing microbial inoculum by adding 10-20 vol.% C.utilis, 10-20 vol.% B.subtilis,10-20 vol.% B.mycoides, 10-20 vol.% S.faecalis, 10-20 vol.% L.casei, 10-20 vol.% A.niger and 10-20 vol.% H.grisea, and culturing microbes, where number of viable cells is 1x 108 colony forming unit/g, (c) adding 5-15 wt.% microbial inoculum obtained in step (b) on mixture obtained in step (a), stirring mixture, and fermenting for 15-25 days, (d) adding 8-15 pts. wt. broadleaf sawdust, 3-8 pts. wt. wheat bran, 3-8 pts. wt. rice bran, 1-3 pts. wt. peat, 1-3 pts. wt. corn flour and 3-8 pts. wt. product obtained in step (c), and mixing mixture, where the mixture has pH of 5-6 and water content of 60-70%.