A novel NLO chromophore with a five-membered heteromatics was synthesized. The chromophore was dispersed into two high-T-g polymers, PEK-C and PES-C. Then they were spin coated onto ITO glass and were poled by employing a corona poling technique. The relaxation behaviour of poled films was studied by using UV-Vis spectra. Good temporal stability was found for all the samples.