We found that the microcavity light-emitting device (LED) shows the emission enhancement having a higher photoluminescence intensity and a narrower linewidth when compared with those of the noncavity LED. We designed the microcavity LED that located the emissive layer and the filler layer between a distributed-feedback mirror and a metal mirror, and fabricated the microcavity LED using a single layer of OxdEH-PPV as emissive material, and measured its photoluminescence characteristics. The experimental results are well fitted to the model that regards the emissive material as the assembly of emitting dipoles.