A novel polyelectrolyte (PLJY) was synthesized based on the azobenzene chromophore containing functional groups (-C=C-) and α-methacrylic acid by radical polymerization. The PLJY was characterized by FT-IR and UV-vis spectroscopy. The thermal property was characterized using the differential scanning calorimeter (DSC). The glass transition temperatures (Tg) was 179.1 oC and showed that the PLJY had excellent thermal stability. Influences of pH values on the UV-Vis absorption spectra of PLJY were studied and polyelectrolyte solution had good pH-sensitivity and H-aggregation behavior. The photoresponsive and thermochromism behaviors were investigated for the azo polyelectrolyte PLJY solution or film. By 256 nm excitation wavelength, the PLJY solution or film appeared photo responsive behavior. At high temperature, the PLJY solution had thermochromic behavior. These results showed that the polyelectrolyte had potential applications in optical information storage and optical switch.