A novel alpha-azide and omega-alkyne A-B type azobenzene monomer, 3'-ethynylphenyl[4-(4-azidobutoxy)phenyl]azobenzene (EAPA), was synthesized and used to generate a novel polymer via step-growth polymerization using 1,3-dipolar cycloaddition reaction under the catalysis of CuSO4 center dot 5H(2)O/sodium ascorbate/H2O ("Click" chemistry). The structure of the resultant main-chain azobenzene polymer, PEAPA, was characterized by GPC, C-13 NMR, UV-vis and FT-IR spectra. Thermal stability and crystallinity of PEAPA powder were studied by TGA and WAXD. The photo-induced trans-cis isomerization of PEAPA and EAPA in N,N'-dimethyl formamide (DMF) solution was investigated. Furthermore, the thermal cis-trans isomerizations of PEAPA and EAPA were also observed at 60 degrees C in dark. Thermal stability and trans-cis-trans isomerization behavior of PEAPA was compared with its non-triazole analog, PDHA. (C) 2009 Elsevier Ltd. All rights reserved.