Two rare metal coordination complexes of yttrium（Ⅲ） including 1,10-phenanthroline, Y（phen）2（NO3）3 and （phenH）2[Y2（pydc）3（NO3）2.6H2O] （phen= 1,10-phenanthroline, pydc=2,6-pyridinedicarboxylate）, and a proton transfer compound （phenH＋）2（pydc2-） were synthesized and characterized by elemental analysis, molar conductance, infrared spectra （IR）, nuclear magnetic resonance （NMR） and thermal analysis. The proposed structures of yttrium complexes were exhibited. The in vitro biological activities of the newly synthesized complexes have also been investigated against Bacillus coli, Staphylococcus aureus and Candida albicans. The results showed that yttrium（Ⅲ） complexes including 1,10-phenanthroline exhibited better antibacterial/antifungal activity than their ligands and corresponding compounds.
