Two-photon absorption (TPA) materials have shown good application prospects in many fields,including three-dimensional optical data storage,three-dimensi onal microfabrication,fluorescence imaging,fluorescent microscopy,frequency up-converted lasing,optical power limiting and photodynamic therapy,and have become the world-wide frontier and focus in the research of photoelectric funct ional materials currently.An all-trans acceptor-donor-acceptor (A-D-A) compound (E,E)-2,2′-[(2,5- dimethoxy-1,4-phenylene)di-2,1-ethenediyl]bis-1H-benzimidazole is design ed and synthesized.Its structure is characterized using Fourier transform infrared an d hydrogen nuclear magnetic resonance spectroscopy,mass spectrometry,and elemental analysis.The linear absorption spectra,single-photon excited fluoresc ence spectra,and fluorescence quantum yields are measured in different solvents.The two-photon absorption and two-photon fluorescent properties are studied using a femtosecond 800nm laser.The results show that with increasing solvent polarity ,the linear absorption wavelengths do not vary significantly,the single-photon exci ted fluorescence wavelengths show bathochromic shifts,and the fluorescence quantum yields decrease.Its fluorescence quantum yield in tetrahydrofuran is 0.93,the two-photon absorption cross-sections is 204×10－50 cm⁴·s·photon －1,and it exhibits strong blue-green two-photon fluorescence.