Objective To extract paralytic shellfish poisoning (PSP) with Supelco ENVI-Carb cartridge, develop a high performance liquid chromatography-mass spectrometry (HPLC-MS/MS) method for determination of PSP in bivalves aquatic products, and provide proof for the detection of PSP in aquatic products. Methods PSP was extracted by 1% acetic acid solution, supernatant added with ammonia (pH=4.0) was loaded on Supelco ENVI-Carb cartridge, and the eluent was dried up. Then the sample was separated on a TSK-GEL Amide column (2.0 mm×250 mm, 5 μm) with water contained 2 mmol/L ammonium formate-50 mmol/L formic acid and 95% acetonitrile contained 2 mmol/L ammonium formate-50 mmol/L formic acid was mobile phase for gradient elution. Detection was carried out by multiple reaction monitoring. Results PSP had a good linear result in the range of 8.1-705.0 μg/kg with detection limit of 10-35 μg/kg in bivalves aquatic products. The recovery was 47.0%-91.3%. Conclusion This method had good performance of extraction and with low matrix inhibition effect. The assay was suitable for trace detection of paralytic shellfish poisoning in bivalves aquatic products.