Objective To provide the limit value of tetrodotoxin in nassariidae for the judgment in regular monitoring.Methods In order to investigate the limit value of tetrodotoxin in nassariidae,the source,content,toxicity,testing standards of tetrodotoxin in nassariidae from relevant documents on tetrodotoxins and paralytic shellfish toxins were compared and analyzed.Results According to the toxicity,nassariidae could be divided into toxic,nontoxic,and seasonal toxic types of nassariidae.The concentration of tetrodotoxin in nassariidae was in the range of 0-177mg/kg.The toxicity of tetrodotoxin is 30 times of paralytic shellfish toxin(comparing their LD50 in mice).Toxic nassariidae(for example,Nassarius rutilans,Zeuxis scalaris,etc.) should be recognized and totally banned to be sold and consumed.The limit value of tetrodotoxin in nontoxic nassariidae and seasonal toxic nassariidae was suggested to be 0.05 mg/kg when tested by the standard method GB/T 23217—2008 Determination of tetrodotoxin in aquatic products.Conclusion The suggested limit value of tetrodotoxin in nassariidae should be reasonable and feasible.The system of monitoring tetrodotoxin in nassariidae has been proposed and perfected.