The sulfonate-containing polyelectrolytes (SPE) from sulfonation of polystyrene (PS) and copolymerization of S-sulfo-propyl methacrylate, potassium salt (SPMS) with styrene (S) were prepared. Photosensitive polyelectrolyte complexes (PECDR) derived from SPE and diazoresin (DR), which does not dissolve in water or organic solvent due to its ionic crosslinking structure, dissolves in aqueous solution of sodium dodecyl sulfate (SDS) due to the dissociation of PEG(DR) and the hydrophobic interaction between SDS and the polymer chain. The photosensitive behavior and thermostability of the PEG(DR) were investigated, and it was found that the thermostability of PEG(DR) increases dramatically in SDS aqueous solution. It was proposed that the higher thermostability of PEG(DR) in SDS aqueous solution is due to an aggregation of SDS molecules around the diazonium group of the PEG(DR), which protects the -N-2(+) group of the DR from attack by the nucleophiles. The image-forming behavior of PEG(DR) by ultraviolet (UV) light was examined and considered to be different from other PECs. It was concluded that the photoimaging behavior of PEG(DR) is based on a reaction in which an ionic bond converts to a covalent bond.