Abstract: 【Objective】 The analysis of Acidovorax citrulli (Ac) to copper stress on transcriptome level response characteristics is helpful to promote the study of copper resistance system and mechanism The results of this study have accumulated basic data for further analysis of the molecular mechanism of copper tolerance of Ac. 【Method】 The copper-resistant FC440 strain of subgroup I of Ac was cultured under copper stress and without copper stress.Then FC440 were collected for RNA-seq to analyze data quality, types of differentially expressed genes (DEGs), KEGG enrichment and Pathway annotation, GO enrichment analysis and other transcriptome features, and verify qPCR. 【Results】 The results showed that 6 FC440 transcriptomic libraries were obtained and total data size was 23.6 Gb; Gene expression analysis showed that the bacteria had 4,344 gene expressions and 466 DEGs were identified (266 up-regulated, 200 down-regulated) ; DEGs were significantly enriched in about 9 major pathways such as transmembrane transport of the ABC transport system, signal transduction of the two-component system pathway, and amino acid metabolism; qPCR analysis results showed that the gene expression trend was consistent with the trend of transcriptome sequencing data. 【Conclusion】 The amino acid metabolism of glutamate and glutathione under copper stress plays an important role in the resistance to copper stress of Ac; the two-component systems participate in the response of Ac to copper ion stress and is negatively affected.There may be anti-copper mechanisms in this bacteria including transmembrane transport of ABC transporters, redox reactions, and intracellular binding precipitation.