With overliming process, most of the furan derivative such as furfural and HMF can be removed completely. Thus, weak acids and phenolic compounds are the dominant inhibitors in the detoxified hydrolysate. Interestingly, the content of acetyl group and lignin in original rice straw are relatively low in comparison with other lignocellulosic feedstock [8]. This characteristic was suggested that the higher ethanol yield maybe achieved in the fermentation of rice straw hydrolysates by P. stipitis due to less weak acids and phenolic compounds released after dilute acid pretreatment. The enzymatic hydrolysis hydrolysate contained 66.2 g/L glucose and 10.3 g/L xylose, and is different with that in acid hydrolysis hydrolysate. Fig. 1 showed that P. stipitis produced 30.8 g/L ethanol with a yield 0.50 g/g at 48 hr from