Abstract: Yessotoxins (YTXs) are marine algal toxins with polycyclic polyethers produced by three species of dinoflagellate and can be accumulated in filter feeding organisms.YTXs were put into the group of diarrhetic shellfish poisoning (DSP), because they often co-existed with okadaic acid (OA) and dinophysistoxins (DTXs) in shellfish.There were the positive results when shellfish were tested with the mouse bioassay method.However, toxicological studies have shown that YTXs can neither induce diarrhea nor inhibit the activity of protein phosphatase, but they have damages on heart, liver and nervous system.Therefore, YTXs have been separated from DSP group.With increasing researches on YTXs, more than 100 homologs have been identified from shellfish and dinoflagellate samples, and the chemical structure of 40 derivatives have been eludicated by high performance liquid chromatography with tandem mass spectrometry (LC-MS/MS) and nuclear magnetic resonance (NMR).In this review, the distribution and toxicology of YTXs and its producer in China coast were reviewed, and some of results on the distribution of YTXs in sea water column were also covered.