In order to reduce the dependency on non-renewable energy sources, as well as decrease problems caused by the accumulation of agricultural residues and the contaminants from their combustion, the production of the second generation of biofuels from rice straw was considered. According to the lignocellulosic structure of rice straw, organosolv pretreatment was performed with 75% (v/v) aqueous ethanol containing 1% w/w sulfuric acid at 150°C for 60min. Then enzymatic hydrolysis by cellulase enzyme was used. In order to maintain the stability and reusability of the enzyme, cellulase from Aspergillus niger (E) and Cellic CTec2 (E2) were immobilized onto graphene oxide sheets which have been coated with magnetic nanoparticles of iron oxide (Fe 3 O 4 -GO) or nickel ferrite (NiFe 2 O 4 -GO). The cellulase immobilization process was performed using various concentrations of cellulase (2, 5 and 10 mg/ml) at different times (2, 4, 6 and 8 h). The immobilization efficiency ranged between 19% and 55% by using the Bradford method and the activity ratio of immobilized enzyme to free enzyme was obtained between 16% and 60% by the 3,5-dinitrosalicylic acid (DNS) test. According to the immobilization efficiency and enzymatic activity, the cellulase concentration of 2 mg/ml and the time of 4 h were chosen as an optimal conditions for the immobilization process. After that, the enzymatic activity of immobilized cellulase was investigated at different pH values (4, 5, 6, 7 and 8) and as a result, pH 5 was determined as an optimal pH. The enzymatic activity of immobilized cellulase was investigated at different temperatures (40, 50, 60, 70 and 80 °C) and 50 °C was determined as an optimal temperature. It should be noted that the optimum pH and temperature of the immobilized enzyme have not been changed in comparison with free enzyme. Thermal stability of immobilized and free enzymes at temperatures of 50 and 60 °C were investigated and the results showed that the immobilized cellulase is more stable than free cellulase, at least 65% of its activity was maintained at 60 °C for 3 h. The kinetic parameters of immobilized cellulase were determined by measuring their activity at various concentrations (0.5, 1, 2 and 2.5 % w/v) of carboxymethyl cellulose as a substrate. The K m values for immobilized enzymes have been slightly increased in comparison with free enzymes. In addition, the V max values for immobilized enzymes have been slightly decreased in comparison with free enzymes. Then the enzymatic hydrolysis on raw and pretreated rice straw was performed by immobilized enzymes of E and E2 for 72 h at 45 °C. Fermentable sugars produced from hydrolyzed rice straw by Immobilized E onto Fe 3 O 4 -GO and NiFe 2 O 4 -GO were equal to 1.92 and 1.88 mg/ml (after the first cycle) and also 1.1 and 1.0 mg/ml (after the second cycle), respectively. In addition, Fermentable sugars produced from hydrolyzed rice straw by immobilized E2 onto NiFe 2 O 4 -GO was equal to 7.2 mg/ml (after the first cycle) and 2.8 mg/ml (after the second cycle). The results have been showed after two cycles of hydrolysis, enzyme immobilization on NiFe 2 O 4 -GO in comparison with Fe 3 O 4 -GO has better reusability and has been produced more fermentable sugars. Keywords: Enzyme Immobilization, Cellulase, Magnetic Nanoparticles, Iron Oxide, Nickel Ferrite, Graphene Oxide, Rice Straw