Abstract: In order to investigate the distribution of the paralytic shellfish poisoning (PSP) toxic algae and the PSP pollution in shellfish in Dapeng'ao cave, Guangdong, PSP toxic algae collected from August 2013 to October 2014 at oyster aquaculture area (S1), outside of oyster aquaculture area (S2) and the bay mouth area (S3) were indentified and PSP toxin in oyster samples synchronously collected were detected.The results showed that three toxic algae species of Alexandrium tamarenses, A. catenella and Gymnodinium catenatum were identified in S2 and S3 sampling sites, but no toxic species were found in S1 site.Cell densities of all the three algae species in S2 and S3 sites were lower, and could not detected in some months.Detection rates of the toxic algae was lower in winter than spring and summer.Eight toxin profiles GTX1, GTX4, GTX5, dcGTX2, dcGTX3, NEO, C1 and C2 were detected in these oyster samples.The detection rate of PSP toxins in oyster was up to 66.7% in winter, and declined in autumn-summer and spring, the highest cell density of toxic algae and detection rates of polluted shellfish were not cogradient in time and the latter lagged behind the former.