The invention relates to a method of making culture medium for Agaricus blazei Murill mushroom, which include the following steps: the sawdust is piled up to 5 to 15 meters high to undergo the first fermentation and decaying process which takes about 3 months; it is required to periodically turn over the sad dust pile every 15 to 30 days; then the dried and sterilized cattle excrements are added to the first-time fermented sawdust to undergo the second fermentation process, wherein the saw dust is piled up to 5 to 15 meters high and the internal fermentation temperature is 70 to 90 degrees centigrade; it is required to periodically turn over the sad dust pile every 15 to 30 days; finally, when the color of fermented sawdust turns dark brown, close to black, and the urine like Ammonia odor disappears, the culture medium can be used as the basic materials of bag-logs for cultivating Agaricus blazei Murill mushroom.
