Using the method of dual-wavelength measurement of platelet [Ca2+]i and Fnra-2 as the Ca2+ fluorophore probe, we measured the effect of acidic Mu copolysaccharide front Sticopus Japonicus Selenka （SJAMP） on platelet [Ca2+]i.The results showed that the most significant increase in platelets [Ca2+]i was seen when the concentration of SJAMP wits 100μg/ml and the elevation of normal platelet [Ca2+]i was 93.96±10.24 nmol/L （n=10）. In the presence of extracellular Ca2+（1 mmol/L）, the magnitude of platelet [Ca2+]i response to SJAMP was increased and the [Ca2+]i could reach 116.72±10.66 nmol/L （n=10）. On the other hand, the magnitude of increased platelet [Ca2+]i induced by SJAMP was smaller and the duration of [Ca2+]i reaching the highest level was longer when compared with other platelet aggregation agents. In the mean time, if platelets were first incubated with cyclooxygenase inhibitor, the rise of [Ca2+]i evoked by SJAMP was inhibited. The results indicated
