The objective of this work is to investigate the effect of aqueous ammonia concentrations and pretreatment temperatures of rice hull to produce bioethanol. Aqueous Ammonia Soaking (AAS) and dilute acid were used to pretreat rice hull. The rice hull composition was analyzed by SEM and Chesson methods. AAS pretreatment was carried out at various aqueous ammonia concentrations of 5, 10, 15, 20, 25 % (v/v) and temperatures of 60, 70, 80 90, 100 oC. The result showed that the highest lignin reduction and glucan recovery were about 61.97%, 88.39%, respectively at ammonia concentration of 20% (v/v) and pretreated temperature of 100 oC. Furthermore, the result produced the highest glucose of about 241.8 mg g-1 and the bioethanol yield of 5.86%