Microwave-assisted pretreatment with sulfuric acid and sodium hydroxide was used to improve sugar yields from corn stover. The optimal conditions for sulfuric acid pretreatment were 190℃ temperature, 10 g/L acid concentration, 3 min pretreatment time, and 20 liquid to solid ratio, resulting in 44.6% sugar yields. For sodium hydroxide pretreatment, the best conditions were 130℃ temperature, 15 g/L alkali concentration, 7 min pretreatment time, and 30 liquid to solid ratio, leading to 80.0% sugar yields.