Polyelectrolyte PTPEPyH,containing tetraphenylethene(TPE)and pyridinium,was synthesized.Its optical properties were investigated with spectroscopies and the results showed that there were two emission-enhanced stages in the interaction between positive-charged PTPEPyH and negative-charged biomacromolecule heparin.The mechanism was very different due to the reduced non-radiative energy loss and the change of surroundings.The polyelectrolyte PTPEPyH,compared with ChS and HA,also showed high selectivity for heparin in the buffer solution and could be used as a potential bio-probe for heparin quantification in the clinical full range.