A novel water\|solube,π conjugated polymer\|poly{(pyrrole\|2,5\|diyl)\[ p\|N[KG-*6],N \|(dimethylamino) benzylidene\]} (PPDMAB) was synthesised.The chemical structutre and properties of the polymer were characterized by EA,XPS,FT\|IR,UV\|vis\|NIR, in\|situ UV\|vis\|NIR spectroscopy,solubility measurement and conductivity measurement.The conductivity of the polymer increased by 2~4 degrees after protonated,H\-2SO\-4\|doped and I\-2\|doped.Reversible change of color (browndark blue) was observed whi...