Effects of different enrichment material on the free amino acid in Artemia nauplii was studied. There were 4 groups, including lysine group, Schizochytrium group, lysine plus Schizochytrium group and control group. The experiment lasted 16 hours, and was sampled every 4 hours. The results showed that the content of free lysine in Artemia nauplii in lysine group was significantly higher than the other groups and 4 times higher than 0h at the end of the experiment. And the content of lysine in Schizochytrium group was the lowest. Except Thr, the content of other free essential amino acids and Asp, Ser, Gly, Tyr in lysine group were significantly higher than other groups. The content of Thr, Ser, Gly, Ala, His and Pro of lysine plus Schizochytrium group decreased as the time prolonged. But in other groups, the content of FAA all increased except Thr. The variation trends of the FAA level in the control group was similar to the lysine plus Schizochytrium group: except Thr, the content of FAA increased at the first 4 h, declined at 8 h, and increased at 12 h. But in lysine group and Schizochytrium group, the content of these FAA in Artemia nauplii increased during the first 8 h, declined at 12 h,and then increased at 16 h.