The delignification process did not improve the pretreated sugarcane straw, therefore the alkaline delignification process is not indicated to increase the enzymatic cellulose conversion of the sugarcane straw pretreated at sever conditions. Hydrothermal pretreatment is enough to obtain reasonable overall yields of the cellulose conversion (50%). According to Silva et al. (2011), the use of hydrothermal pretreatment for sugarcane bagasse was also enough to convert 50% of cellulose into glucose-rich hydrolysate.Therefore, is possible to conclude that the pretreatment step of sugarcane straw at 190◦C during 10 min lead to higher cellulose conversions. Instead of expected, the delignification step is not profitable for sugarcane straw, do not leading to improvements in the enzymatic cellulose conversion.