In this paper, we succeed in fabricating high-temperature fiber of polysulfonamide/ZnO. Polysulfonamide/ZnO nanocomposite was prepared by in-situ polymerization. Some studies and characterization of Polysulfonamide/ Zinc oxide nanocomposite with ZnO 0.5% have been done. It includes ηr, Crystal degree and thermal property. Experiment’s results showed that, ZnO as filler can improve crystal degree of polysulfonamide fiber. The crystal degree has been improved, from lower than 20% up to 27%. ηr of polysulfonamide/ Zinc oxide nanocomposite solution with ZnO 0.5% is 2.03. The maximum weight loss of the nanocomposite occurred at 453.5 ℃ . In this paper, we succeed in fabricating high-temperature fiber of polysulfonamide / ZnO. Polysulfonamide / ZnO nanocomposite was prepared by in-situ polymerization. Some studies and characterization of Polysulfonamide / Zinc oxide nanocomposite with ZnO 0.5% have been done. It includes ηr , Crystal degree and thermal property. Experiment’s results showed that, ZnO as filler can improve crystal degree of polysulfonamide fiber. The crystal degree has been improved, from lower than 20% up to 27%. Ηr of polysulfonamide / Zinc oxide nanocomposite solution with ZnO 0.5% is 2.03. The maximum weight loss of the nanocomposite occurred at 453.5 ° C.