PSP is one of the most important shellfish poisonings because of its acuteness of the symptoms, wide distribution, and high fatality. In the areas where shellfish are contaminated with PSP toxins, shellfish toxicities are monitored to avoid the poisoning. Currently , mouse bioassay is applied for detection of shellfish toxins in many countries. This is a simple and reliable method, but has many problems because of the animal assay. The cost of the assay also increases an economic loss of PSP problems. Therefore, a simple, rapid and cheap method for toxin detection is needed. For this purpose, ELISA is the first candidate. However, the antibody to detect various toxin components could hardly be obtained. Previously, we reported the formation of a stable conjugate, in which C11 atom of STXs and sulfur atom of thiols are covalently bound, in the course of the transformation of gonyauatoxins to saxitoxins by thiol compounds such as glutathione. In the present study, we tried to obtain the antibody using the antigen in which carrier protein was introduced to amino group of glutathione bound to C11 of saxitoxin. Although the activity to react with toxins was low, the antibody obtained reacted with all the toxin components examined almost equally.