Due to the high cost of YE, DSY4.5 and DSY9, containing the same amount of total nitrogen as found in YE3 and YE6, respectively, were employed.The results showed that the P, Q and Y values of DSY4.5 and DSY9 were similar to those of YE3 and YE6, respectively. The Q values of DSY4.5 and DSY9 were 3.11 and 3.92 gl h , respectively. These results clearly indicated that both nitrogen supplements did not have a positive effect on yeast growth but they promoted the rate of ethanol production or the ethanol productivity under the high gravity fermentation. Although the total nitrogen content of YE3 and YE6 were equal to those of DSY4.5 and DSY9, respectively, the initial assimilable nitrogen contents were different (table 1).