A new europium complex Eu(tta)3L1(la)based on 1,10-phenanthroline derivative(L1 =(2-(3,5-dimethoxyphenyl)-1H-imidazo[4,5-f][1,10]phenanthroline),tta = 2-thenoyltrifluoroacetone)was designed and synthesized.Its structure was characterized by 1H and 13C NMR,elemental analysis,UV-vis,fluorescence spectra and single crystal X-ray diffraction.The crystal of the complex la belongs to monoclinic system with the space group P21/n.The europium complex 1a in the solid and in the solution displays the typical emission of Eu(Ⅲ)ion centered at 612 nm as a result of the electric dipole transition(5Do→ 7F2).It exhibits high quantum yield(20.42％),long lifetime(0.29 ms)and good C1E color coor-dinate(0.67,0.33)in solid.In addition,the complex shows high sensitivity and selectivity towards Al3+and Zn2+in methanol solution which can be attributed to the Al3+/Zn2+cation instead of Eu3+in the complex 1a.The LODs for Al3+and Zn2+were calculated to be 5.880 × 10-7 and 7.678 × 10-8 mol/L,respectively.Besides,the additions of Al3+and Zn2+express remarkable color changes from red to bright blue and ivory that can be clearly observed by the naked eye respectively.