The one-photon and two-photon excited UV fluorescence spectra of 1, 10-phenanthroline and ［bis(1, 10-phenanthroline)lanthanum］ nitrate are observed in the methanol solution. It is found that the UV fluorescence intensity of 1, 10-phenanthroline is obviously enhanced by virtue of its coordination with La3+, and the effect of La3+ as the role of a bridge improves the coupling process between two 1, 10-phenanthrolines in a complex, which results in the movement of the UV fluorescence peaks to longer wavelength.