With improved thermostability and wider pH range of the new glucoamylase from Trichoderma reesei(TrGA),the ethanol production was carried out without any pH adjustment.Using cassava chip flour as an example,conventional ethanol production process was modified.Liquefaction,pre-saccharification and fermentation were conducted under pH5.5.i n addition to that the temperature of pre-saccharification was also increased from 60℃ to 65-70℃.Compared with the conventional ethanol process,the modified process under such conditions DS-25% and TrGA-100unit/gds,can speed up the presaccharification and ethanol fermentation rates,and increase ethanol productivity(8.4%).Moreover,the removal of pH adjustment simplifies the process,saves on chemicals and reduces the risk of contamination.