For better use of potato flour on ethanol production,the different factors affecting the enzymatic liquefied of potato flour was studied. The optimum condition was investigated by viscosity, after the single factor and orthogonal experiments, a study of pH,water content,time, temperature, grinding degree, a-amylase amount was carried on. The optimum conditions for liquidation was as follows : pH was 6.0,glinding degrees was over 40 mesh sieve ,temperature was 90℃,the time was 60min. The use of heat-resisting a-amylase amount was 8u/g,water content was 105mL T...