Synthesis of rare-earth chelate is a key part of homogeneous time-resolved fluorescence immunoassay. To synthesize optimal rare-earth chelate, we select diethyl 2,6-dibromomethyl-3,5-pyridinecarboxylate as raw material and optimally synthesize Li+2,6-{N,N’,N,N’-［bis(2,2’-bipyridine-6,6’-dimethyl)］ bis(aminomethyl)}-pyridine-3,5-diethyl diester, and then the spectral difference of europium cryptate synthesized by the different reactive systems of acetonitrile and methyl alcohol are discussed. Studies show the excitation spectra(the maximum excitation wavelength is 310 nm), emission spectra(the maximum emission wavelength is 616 nm) and quantum yield of europium cryptate synthesized by the different reactive systems are consistent. Fluorescence intensity are linear with the concentration of europium in the range of 10-8～10-5 mol·L-1 (R2=0.993 73, 0.986 65), respectively. But the fluorescence intensity between them (c=2.5×10-5 mol·L-1) are slightly different. Their fluorescence lifetime are 825 and 830 μs, respectively. Therefore, europium cryptate synthesized has big Stoke’s shift, high fluorescence intensity, long fluorescence lifetime and so on. Pyridine-2,2-bipyridine in europium cryptate can protect europium from interference. It is an ideal europium cryptate used for the labeling of biomolecules such as protein, nucleic acid. This study not only expands the synthesis of new rare earth chelate, but also lays the foundation for the establishment of homogeneous time-resolved fluorescence immunoassay.