NOVELTY - Use of straw is claimed for cultivation of Pleurotus ostreatus.    USE - The straw is useful for cultivation of P.ostreatus (claimed).    ADVANTAGE - The straw is effectively utilized as raw material for cultivation of the P.ostreatus in a cost-effective manner, provides high yield of the P.ostreatus, and significantly increases biological efficiency of the P.ostreatus up to 140-180%, and economic and social benefits.    DETAILED DESCRIPTION - Use of straw is claimed for cultivation of Pleurotus ostreatus. The cultivation is performed by (a) selecting time period between August to September, taking cleaned raw materials comprising 100 kg straw, 0.5-1 kg urea, 1-2 kg calcium superphosphate, 2-4 kg quicklime powder, 100-150 g crab shell powder, 50-100 g dry Camellia sinensis powder and 30-60 g castor seed powder, mixing the urea and calcium superphosphate in the above-mentioned weight proportions with 100-150 kg water, stirring materials uniformly to obtain solution (A), mixing the quicklime powder, crab shell powder, dry C.sinensis powder and castor seed powder in the above-mentioned weight proportions with 50-80 kg water, stirring materials uniformly to obtain solution (B), spreading the straw flat on cemented floor, adding the solution (A) on the straw, turning and beating the straw continuously, stacking straw mixture into heaps, covering the heaps with grass, allowing fermentation to occur for 10-15 hours, spraying the solution (B) uniformly on stacked material, fermenting the material for 6-8 days, turning the material for 2-3 times and fermenting the straw until the straw becomes soft and faint smell starts coming from fermented straw material, (b) taking enormous amount (in kg) of plastic film having width of 3.5-4 m and big wooden board having length of 1.3-1.5 m, width of 1.5-2 m and height of 0.4-0.6 m and forming shed by cleaning ground, spreading a layer of lime powder on cleaned ground, covering the layer with a thin film, fixing relatively 2 large wooden boards in mid portion of the film, leaving 1.4-1.6 m wider distance on each side of the layer, forming bottom portion using small wooden planks fixed between the large wooden boards with width of 50-60 cm, where width of formed shed is 30-40 cm, (c) preparing substrate for fast growth and high yield of the P.ostreatus by taking 100 kg straw per 10-15 kg P.ostreatus, sprinkling layer of nutritional soil up to a thickness of 0.5-1 cm on the ground, spreading 15-20 cm thick layer of fermented rice straw on the soil, sprinkling a layer of P.ostreatus mycelium on the straw, repeating the above-mentioned steps several times, removing the straw up to a height of 1.2-1.4 m such that content of the P.ostreatus remains up to 15-25% in bottom portion and 20-30% on the top portion, sealing the top portion, covering both sides of the straw with film, pricking the film with needle to form 100 small holes on the film for facilitating aeration to the P.ostreatus, allowing spawning to occur, maintaining relative humidity at 70-80% inside the heaps and allowing hyphae to grow under greenhouse conditions at 20-30 degrees C for 20-25 days until whole surface of the straw gets covered with the P.ostreatus hyphae, and (d) opening the film, preventing over-heating of developed hyphae, drilling hole up to a depth of 20-30 cm with diameter of 2-3 cm on both side of the walls, cooling the walls by spraying water through nozzle of the sprayer into the holes and further spraying nutrient solution at a rate of 1-2 kg/m2 on the hyphae, where the nutrient solution is prepared by (i) adding and mixing 200-250 g sugar, 150-200 g urea, 200-250 g calcium superphosphate and 10-15 g potassium dihydrogen phosphate per 50 kg water, or (b) adding and mixing 40-60 g urea and 500-600 g sugar per 50 kg water.