NOVELTY - Use of coconut chaff bedding material is claimed, in preparation of Agaricus bisporus or A.blazei culture composition. The culture composition is prepared by crushing coconut husk, mixing coconut husk powder, bran and straw, adding water to mixture to obtain coconut chaff bedding material, mixing urea with e.g. coconut chaff bedding material and lime, stacking and fermenting obtained mixture, spraying water on crushed straw, sprinkling lime on obtained mixture, processing mixture, mixing obtained products, and fermenting and processing mixture.    USE - The coconut chaff bedding material is useful in preparation of A.bisporus or A.blazei culture composition (claimed).    ADVANTAGE - The coconut chaff bedding material cost-effectively improves yield of A.bisporus or A.blazei having high quality. The method avoids usage of cow dung, consumes less time, saves labor, and is environmentally-friendly to perform. The utilization amount of straw is reduced.    DETAILED DESCRIPTION - Use of coconut chaff bedding material is claimed, in preparation of Agaricus bisporus or A.blazei culture composition. The culture composition is prepared by (a) crushing coconut husk, mixing 55-65 pts. wt. coconut husk powder, 30-35 pts. wt. bran and 9-12 pts. wt. straw, adding water to mixture, and controlling water content of the mixture reaches 28-32% to obtain coconut chaff bedding material, (b) collecting 25-35 pts. wt. coconut chaff bedding material which is used for 18-24 months, 40-60 pts. wt. Pleurotus eryngii residue, 0.1-0.2 pt. wt. edible salt, 0.4-0.5 pt. wt. calcium superphosphate, 0.7-0.8 pt. wt. ammonium bicarbonate and 1-1.2 pts. wt. lime, adding 0.3-0.4 pt. wt. urea, regulating ratio of carbon and nitrogen of urea to 18-20:1, controlling water content of the coconut chaff bedding material is 25-30%, and washing the P.eryngii residue for removing spores, (c) mixing components of step (b), stacking obtained mixture to a height of 1.2-1.3 m and width of 1.5-1.6 m, fermenting the mixture for 10 days, and turning the mixture once for interval of 4 days, 3 days or 3 days, (d) crushing 15-20 pts. wt. straw to a size of 8-10 cm, spraying water on crushed straw, sprinkling lime on obtained mixture, and covering the mixture using thin film, and processing mixture for not less than 7 days, where weight ratio of the crushed straw and lime is 90-110:6, (e) mixing products obtained in steps (c) and (d), stacking obtained mixture, and fermenting the mixture for 5-7 days, and (f) again performing above-mentioned step (e), adding obtained product to reactor, maintaining temperature of the reactor at 58-62 degrees C for not less than 10 hours, reducing the temperature to 50-52 degrees C, and processing obtained product for 5-6 days. An INDEPENDENT CLAIM is included for method for using the coconut chaff bedding material in preparation of A.bisporus or A.blazei culture composition, which involves performing above-mentioned steps (a)-(f).