Butanol fermentation from corncob was achieved using an integrated process combining wet disk milling (WDM) pretreatment with enzymatic hydrolysis and fermentation.Pretreated corncob was easily hydrolyzed and the yields of glucose and xylose were 71.3% and 39.1%, respectively.At the same time, the feasibility of particle-size distribution if it could be used to determine the effect of WDM pretreatment rapidly and precisely was discussed.SHF and SSF mode were implied to produce butanol using pretreated corncob.Fermentation of pretreated corncob hydrolysate resulted in the production of 9.0 g L-1 butanol and utilized 39.4 g L-1 sugars which was similar with the pure sugar fermentation, suggesting that the there were not any inhibitors revealed in the pretreatment process.Comparing to SHF fermentation, a low butanol concentration (7.8 g L-1) was generally observed using the SSF mode because of the deficiently enzymatic hydrolysis.