Abstract: In the water-insoluble polyelectrolyte complex of 2,10-Br and sodium polyacrylate the ratio of[COO~-]/[(?)] was found to be 6/4(equivalent ratio),which maintained constant even the total original concentration of polymers ranged from 1×10~(-4) to 1×10~(-2) mol L~(-1). In the KBr solution of high ionic strength the insoluble complex was dissolved due to the "shielding effect" of counterions. In water complexation could take place instantly and completely producing a stable complex. However the formatiom of complex developed with time in aqueous salt solution. The biological activity of the ionenes has been tested preliminarily. 2,6-Br, 2,10-Br and 6,10-Br could inhibit the growth of E.coli, of which 6,10-Br is most effective.