The　profiling　of　the　most　lethal　paralytic　shellfish　poisoning　toxins　(PSTs)　in　freshwater　has　increased　the　need　to　establish　an　alternative　analytical　method　with　high　sensitivity　and　resolution.　In　this　paper,　a　coupling　technique　of　field-amplified　sample　injection　(FASI)　and　CE　with　end-column　amperometric　detection　(CE-AD)　was　developed　to　improve　the　detection　sensitivity　and　separation　of　PSTs　by　electrokinetically　injecting　a　water　plug　of　analytes　to　the　capillary　filled　with　a　high-conductivity　BGE.　Parameters　affecting　FASI　and　CE　process　were　carefully　adjusted　to　achieve　the　highest　response　and　resolution.　Separation　selectivity　for　PSTs,　especially　for　the　analogues　and　epimers,　was　greatly　enhanced　by　using　40　mM　Britton-Robinson　buffer　(pH　9.5)　as　BGE,　which　altered　the　EOF　and　mobility　of　the　analytes　that　interacted　with　polyborate　ions.　Satisfactory　linear　relationship　between　peak　current　and　concentration　of　toxins　were　gained　over　a　wide　range　of　1.95-254　mu　g/L.　The　detection　limits　(S/N　=　3)　for　five　PSTs　ranged　from　0.63　to　3.11　mu　g/L,　which　are　below　the　health　alert　level　in　drinking　water.　In　comparison　with　the　up-to-date　reporting　chromatographic　methods,　the　FASI-CE-AD　method　was　simple,　low-cost,　selective,　and　sensitive　enough　for　direct　quantification　of　PSTs　at　very　low　levels,　implying　a　potential　for　screening　and　monitoring　of　PSTs　in　surface　waters.