By using a composite subphase, the atypical amphiphilic Tb(acac)(3)Phen (where acac denotes acetylacetone and Phen denotes 1,10-phenanthroline) molecules without long hydrophobic chains were deposited onto solid substrates. The results of UV-vis spectra and fluorescence emission spectra show the Tb(acac)(3)Phen/arachidic acid (1:1 molar ratio) Langmuir-Blodgett (LB) film to be homogeneous in direction normal to the substrate. A periodic layer structure of the LB film is demonstrated by low-angle X-ray diffraction results, the average layer spacing being 5.40 nm. The LB film containing Tb(acac)(3)Phen can emit strong green fluorescence, and the fluorescence signal can be detected from a single layer. The wavelengths of fluorescence emission are not altered in the ordered molecular film; however, the fluorescence intensities of some emission peaks are increased.