A series of rare-earth europium organic coordination complexes with the general formula EuL3phen·H2O(where the first free ligand L=PMBA, PCBA, PBrBA, PABA, the second free ligand phen=1,10-phenanthroline; PMBA=p-methylbenzoic acid, PCBA=p-chlorobenzoic acid, PBrBA=p-bromobenzoic acid, PABA=p-aminobenzoic acid) are prepared via solvothermal synthesis procedure. The composition and structure of the resulting complexes are investigated by various means including elemental analysis, infrared (IR) spectroscopy and thermogravimetric analysis. All the aromatic carboxylic acid ligands and phen are coordinated to Eu3 + . In addition, the europium complex doesn′t decompose until 318 ℃，which indicates that the complex has a good thermal stabilization. The absorption properties of ultraviolet light of four kinds of aromatic carboxylic acid ligands are studied. The luminescence properties of the complexes have been characterized by fluorescence spectroscopy. All the complexes can emit characteristic luminescence of Eu3+ ion, and the emission intensity of electronic-dipole transition(5D0→7F2) of the complexes Eu(PBrBA)3phen·H2O, Eu(PMBA)3phen·H2O, Eu(PCBA)3phen·H2O, and Eu(PABA)3phen·H2O in turn decreased. The international commission on illumination (CIE) chromaticity coordinates of the complexes are in the red region, and they can also emit pure red light.