In order to investigate the adaptive changes of crucian carp(Carassius auratus)to hypoxia,gill tissues treated with hypoxia(dissolved oxygen 0.6 mg/L±0.2 mg/L,water temperature 16 ℃±0.5 ℃)for 0 h and 96 h and were subjected to transcriptome sequencing by RNA-seq,and a total of 40.22 Gbp Clean Base was obtained,and 93%~96%of bases in each sample had a mass value greater than Q30.Differential analysis yielded a total of 7 142 differential genes(|log2 FoldChange|≥1 and FDR<0.05).GO functional enrichment analysis showed that the differentially expressed genes were significantly enriched mainly in DNA replication initiation,MCM complex,etc.KEGG pathway en-richment analysis showed that the differentially expressed genes were mainly in DNA replication,VEGF signaling pathway,necrotic apoptosis and other functions.In summary,vegf,vegfb,hba,hbb,mcm2-mcm6,ripk3 and other genes are the key genes for 96 h hypoxia adaptation in crucian carp.