is an important mariculture species in China. In aquaculture environments ammonia is a common toxic substance. higher frequencies of ammonia nitrogen toxicity in shrimps have been reported. Thereforeit is necessary to investigate ammonia metabolism by. As an important member of the AAT-like familythe enzyme aspartate aminotransferase (GOT) is involved in many aspects of ammonia metabolism including participating in inosine monophosphate transdeamination, detailed understanding of the regulation of GOT is of great significance. In this studywe successfully cloned the aspartate aminotransferase cDNA of -untranslated region(UTR) of 83 bp, protein exhibited typical AAT-like family features-phosphate binding sites suggesting that it belongs to the AAT-I superfamily. Homology analysis revealed that the amino acid sequence of was highly conserved with its homologs of other arthropods. The similarities of respectively. Phylogenetic analysis showed that . Tissue expression analysis showed that heart and lymph. The highest expression level of FcGOT in chinensis, 48 and 72 h after exposure to different concentrations of ammonia nitrogen. The expression of the gene was significantlydifferent compared with the control group (and the expression conditions differed between hepatopancreas and gill. In hepatopancreasps were exposed to 16and down-regulated after treatment with 4 mg/L ammonia-N for 48 h. In gill tissueambient ammonia stress and reached a peak at 12The reason for the discrepant expression between the two tissues may be that the gene expressions were affected by organizational distance. The results imply that metabolism and be involved in responses to acute ammonia stress.