A tripodal ligand, 2-acetylpyridine-tris(2-aminoethyl)amine (L), pyridine-N-oxide and their ternary complexes with rare earth nitrates have been synthesized. These new complexes with the general formula of Ln·L·PyNO·(NO3)3·nH2O (where Ln = La, Nd, Tb, Pr, Eu, n = 1~3 ) were characterized by elemental analysis, IR spectra, thermal analysis and molar conductivity. All the complexes are stable in air. The results show that the lanthanide ions in each complex are coordinated by nitrogen atoms of the ligand, oxygen atoms of PyNO and the nitrates. The fluorescent properties of the Eu(III) and Tb(III) complexes in solid were investigated.