Abstract: To explore the effect of adrenaline on Grass Carp Reovirus type II (GCRV-II) infection, this study was based on a research model of rare minnow infected with GCRV-JX02. Methods including reverse transcription-quantitative polymerase chain reaction (RT-qPCR), Western Blot (WB), and Enzyme-Linked Immunosorbent Assay (ELISA) were employed to investigate the role of adrenaline in the heat shock response and GCRV-JX02 infection in the host. The results showed that following an intraperitoneal injection of adrenaline at a concentration of 5×10^–6 mg/μL in rare minnow, the internal adrenaline levels initially increased and then decreased, with the peak concentration observed at 30min post-injection. Liver, intestine, brain, and muscle tissues were collected at 0, 15min, 30min, 45min, and 60min post-injection, and HSP70 expression was detected by RT-qPCR and WB. It was found that the expression of HSP70 in liver and brain tissues increased over time, reaching the highest level at 45min before declining. Western blot analysis confirmed that HSP70 expression at the transcriptional and translational levels increased over time in liver and brain tissues. Furthermore, when adrenaline (5×10^–6 mg/μL) was co-injected with GCRV-JX02 (2.1×10⁵ particles/μL), the mortality rate of rare minnow significantly increased, and the time of death was advanced. The results of the study indicate that adrenaline injection induces a heat shock response in rare minnow, significantly upregulating HSP70 expression and enhancing the susceptibility of rare minnow to GCRV-JX02 infection. This study establishes a stress model of intraperitoneal injection of adrenaline in rare minnow, elucidating how adrenaline accelerates the infection process of GCRV-II in hosts, contributing to a better understanding of the role of stress responses in the prevalence of hemorrhagic disease in grass carp. Additionally, it provides new insights and theoretical foundations for the prevention and control of GCRV in grass carp.