Abstract: 【Objective】 To explore the effects of ultraviolet B（UVB） radiation on the skin of Odontobutis sinensis during intensive high-density shallow water aquaculture, which could provide theoretical support for the study of the mechanism of resistance to ultraviolet radiation and the development of maintenance measures for freshwater benthic fish in artificial aquaculture environments. 【Method】 The Odontobutis sinensis was used as the experimental material, with a UVB radiation intensity of 3 W/m² and radiation time of 0 h（before radiation）, 4 h, 8 h, 12 h. Skin tissue samples were collected from the same position on the back of Odontobutis sinensis, and tissue sections were observed, melanin and DNA damage related indicators were measured, followed by transcriptome sequencing. Differentially expressed genes（DEGs） in the skin of Odontobutis sinensis before and after 12 h of UVB radiation were screened, and the effects of UVB radiation on melanin synthesis and DNA damage repair pathways were studied. 【Result】 With the prolongation of UVB radiation time, the distribution of melanin on the back skin of Odontobutis sinensis became more dense, and the distribution area, content of melanin and tyrosinase activity all showed an increasing trend. At 12 h of UVB radiation, the distribution area of melanin was the highest（12165.39 μm²）, the content of melanin was the highest（42.58 ng/L）, and the tyrosinase activity was the highest（7.27 U/mL）, with significant differences between each time point（P＜0.05）. With the prolongation of UVB radiation time, the DNA damage related indicators of cyclobutane pyrimidine dimers（CPD） and 6-4 PP in the skin of Odontobutis sinensis showed a trend of first increasing and then decreasing. They reached their peak at 4 hours of UVB radiation, with CPD content of 8.98 mg/mL and pyrimidine（6-4） pyrimidone photoproducts（6-4 PP） content of 153.46 pg/mL, but there was no significant difference between each radiation time points（P＞0.05）. The transcriptome sequencing analysis showed that there were a total of 1584 shared DEGs between the skin tissues of Odontobutis sinensis exposed to UVB radiation for 12 h and before UVB radiation. Among them, 1055 DEGs were upregulated and 529 DEGs were down-regulated. The KEGG signaling pathway enrichment analysis results showed that the 9 melanin synthesis related DEGs mainly involved in the cAMP/PKA signaling pathway, Wnt/β-Catenin signaling pathway, SCF/c-KIT signaling pathway and ET-1/ETB-R signaling pathway, while 17 DNA damage repair related DEGs mainly involved in homologous recombination, nucleotide excision repair, mismatch repair, and Fanconi anemia pathway. 【Conclusion】 After being exposed to UVB radiation, the distribution of melanin in the skin of Odontobutis sinensis is more dense. It may resist UVB radiation by regulating the melanin synthesis pathway to increase the melanin content in the skin, and repair damaged DNA by up-regulating the expression of DNA damage repair related genes.