Novel Eu(III) complex derivatives for laser medium were synthesized and investigated. The photophysical properties (emission spectra and lifetimes) were depend on ligand structures. The emission from the edge of the polymer thin films containing those complexes decayed following single- exponential kinetics at the lowest excitation power. While the emission decays at high excitation energy consisted of normal component and a faster component. The ratio of the faster component increased with increasing excitation energy. These observations indicate that the faster component is due to amplified spontaneous emission from the complexes in the microcavity.