ObjectiveTo investigate the inhibitory effects and mechanisms of Xiayuxue Tang （XYXT） on hepatocellular carcinoma cells through the regulation of succinate metabolism and succinylation modification. MethodsXYXT-medicated serum was prepared. The effects of different concentrations of succinate on the proliferation of HepG2 and MHCC97H cells were observed using the cell counting kit-8 （CCK-8） assay， and the experimental concentrations for subsequent tests were determined. Further CCK-8 assays were performed to evaluate the effects of XYXT-medicated serum of different concentrations （5%， 10%， and 15%） on cell proliferation. Flow cytometry， scratch test， and Transwell assay were employed to analyze the effect of 10% XYXT-medicated serum on the cell cycle， migration， invasion， and apoptosis. The changes in succinate metabolism and succinylation modification were examined based on succinate content assays， succinate dehydrogenase （SDH） activity detection， and western blot. The expressions of Yes-associated protein 1 （YAP1） and sirtuin 5 （SIRT5） were detected via Real-time PCR and western blot. Molecular docking was applied to validate the binding between XYXT’s main components and target proteins. ResultsCompared with the control group， 1-2 mmol·L^-¹ succinate significantly promoted HepG2 and MHCC97H cell proliferation （P<0.01）. XYXT-medicated serum （5%， 10%， and 15%） markedly inhibited the proliferation of both cell lines compared with the blank group （P<0.05， P<0.01）. Treatment with 10% XYXT-medicated serum arrested the cell cycle at the stage prior to DNA synthesis （G₀/G₁） （P<0.01）， suppressed migration （P<0.01） and invasion （P<0.05， P<0.01）， and promoted apoptosis of HepG2 and MHCC97H cells （P<0.01）. Co-treatment with XYXT and succinate reversed the inhibitory effects of XYXT on proliferation， migration， and invasion of HepG2 and MHCC97H cells （P<0.05， P<0.01）. The proportion of cells at G₀/G₁ phase decreased （P<0.01）， and the apoptosis rate decreased （P<0.01）. In terms of succinate metabolism， compared with the blank serum group， the 10% XYXT-medicated serum reduced succinate levels of HepG2 and MHCC97H cells （P<0.05， P<0.01）， enhanced SDH activity （P<0.01）， and downregulated succinylation modification. In terms of YAP1/SIRT5 pathway， compared with the blank serum group， the 10% XYXT-medicated serum significantly downregulated the mRNA and protein expressions of YAP1 in HepG2 and MHCC97H cells （P<0.05， P<0.01） while significantly upregulated the mRNA and protein expressions of SIRT5 （P<0.05， P<0.01）. Molecular docking confirmed that there was a good binding ability between YAP1 and SIRT5， as well as between XYXT's main active components and YAP1 and SIRT5. ConclusionXYXT suppresses hepatocellular carcinoma cells by modulating the YAP1/SIRT5 signaling axis to intervene in succinate metabolism and succinylation modification.