Abstract: ObjectiveTo develop a cell bioassy to detect paralytic shellfish poison.MethodsUtilizing the sodium channel blocking character of saxtoxin,the standard curve between paralytic shellfish poison and optical density value was constructed.ResultsThe average optical density value of Ouabain/veratridine control group was 0.385 0.The dosage of saxitoxin had a linear correlation with optical density value and the regression equation was y=0.399 6+0.503x(r=0.988 0,P<0.02).ConclusionWithin 0-016ng of saxitoxin,there was a dose-response relationship between the dosage of saxoxin and optical density value.The detecting method of the cell bioassay could be used to detect the toxins of paralytic shellfish poison.