Tetrodotoxin (TTX) rapid test kit is based on sandwich lateral flow immunochromatographic assay. The test device has a testing window. The testing window has an invisible T (test) zone and C (control) zone. When sample is applied into the sample hole on the device, the liquid will laterally flow on the surface of the test strip. If there is little Tetrodotoxin (TTX) in the sample, a visible T band will appear; T band is invisible if it has more Tetrodotoxin (TTX) in the sample. The C band should always appear after a sample is applied, indicating a valid result. By this means, the device can accurately indicate the presence of Tetrodotoxin (TTX) in the sample.