In order to investigate the tetrodotoxin(TTX) content in the tissues of Takifugu obscurus and the expression characteristics of voltage gated sodium channel genes in toxic tissues, this study used enzyme-linked immunosorbent assay (ELISA) to determine the TTX content in 8 tissues, including the liver and heart of Takifugu obscurus. Real time fluorescence quantification (RT-qPCR) was used to detect the relative expression of voltage gated sodium channels α subunit gene family, including scn1aa, scn1ab, scn4aa, scn4ab, scn5aa, scn5ab, scn8aa, and scn8ab in various tissues. The results showed that the TTX content in various tissues ranged from high to low, including brain (9.521 ±2.816) μg/g, heart (4.271 ±1.129) μg/g, gills (1.586 ±0.527) μg/g, muscle (1.494 ±0.938) μg/g, liver (0.913 ±0.206) μg/g, skin (0.902 ±0.235) μg/g, intestine (0.894 ±0.215) μg/g, and eye (0.864 ±0.287) μg/g. Brain and heart tissues were weakly toxic, while liver, skin, muscle, eye, intestine, and gill tissues were slightly toxic. The RT-qPCR results showed that the relative expression levels of scn1aa, scn1ab, scn4ab, scn5aa, scn5ab, scn8aa, and scn8ab genes were the highest in liver tissue. The scn4aa gene was only expressed in muscle tissue, and only the scn4ab gene was expressed in skin tissue. Moreover, the scn4ab gene was expressed in all detected tissue types, indicating widespread expression. It is discovered that there are differences in the expression characteristics of sodium channel genes between zebrafish and Takifugu obscurus tissues.