The compound 4-(4-chlorophenyl)-2,6-diphenylpyridine was synthesized by one-pot in potassium hydroxide and aqueous ammonia solution from 4-chlorobenzaldehyde and acetophenone. The title compound was characterized by 1H NMR, 13C NMR and FTIR(Fourier Transform Infrared Spectroscopy). The pH titration indicated that the title compound was strong sensitive to pH in absorption spectra and fluorescence spectra. The absorption intensities at 256 nm decreased upon pH variation from 4.70 to 4.22. At the mean time, both the absorption intensities at 312 nm and the emission intensities at 403 nm gradually increased. The thermal property of the title compound was also measured and high thermal stability was demonstrated.