Species of mushroom are considered as a source of protein and possessing high medicinal and economical values. This study was carried out in growth chamber on Pleurotus ostreatus L. strain 66 to investigate the effect of different levels of supplements on yield quantity and quality during the two seasons of 2016/2017 and 2017/2018. Four supplements with three levels of each one was used in this investigation i.e. wheat and rice bran were added the levels of 5, 15 and 25%, while the urea and zinc sulfate were added the levels of 0.5, 1.5 and 2.5% were examined. The obtained results showed that, wheat bran with the second level gave the highest number of fruits/bag, total weight of fruits and biological efficiency/bag in the both seasons, respectively. While the lowest number of fruits/bag, total weight of fruits and biological efficiency/bag was noted from urea with the third level in the both seasons respectively. The highest stalk length was obtained from urea with the third level in the both seasons. While the largest stalk and fruit bodies diameters resulted from wheat bran with second level during both experimental seasons. The highest nutritional values of potassium and fat were obtained from rice bran with second level. The wheat bran with second level gave the highest value of protein and energy content. On contrast, the lowest results for protein and energy content were obtained from urea and the third level. The obtained results showed that the control gave the lowest value of potassium and fat content. These results recommended that the best yield and quality were obtained from wheat bran with second level of this supplement. The wheat and rice bran supplements increased the oyster mushroom productivity and quality.