Abstract: Histone deacetylases（HDACs）, important members of the epigenetic enzymes, play an important role in cellular transcriptional regulation through deacetylation of nuclear histones. However, their roles in fish physiology have been little explored. This study was designed to synthesize shRNA of zebrfish HDAC8, construct pLKO.1-hdac8-shRNA recombinant plasmid by Eco RⅠ and AgeⅠenzyme digestion, and a negative control recombinant plasmid（nc） at the same time. Then, two lentivirus packaging plasmids, pCMV-VSVG and pCMV-Dr8.91, were co-transfected into HEK-293 T cells for virus packaging, respectively. RT-qPCR detection showed that hdac8 was successfully knocked down. The survival rate of ZF4 cells was detected by trypan blue staining, and the expression of apoptosis-related genes bax, bcl2 and caspase-3 were further detected. The results showed that the survival rate of hdac8 knockdown cells was significantly lower than that of nc cells（P＜0.05）, and the expression of apoptosisrelated genes bax and caspase-3 in hdac8 knockdown cells was significantly up-regulated, suggesting that the increased cell mortality by knocking down hdac8 was caused by up-regulation of apoptosis. This study provided a basis for further study on the mechanism of zebrafish HDAC8 during growth and development process and under the environmental pressure.