A new lanthanide coordination polymer, ［Eu(2-stp)(2,2’-bipy)(H2O)］·H2O (2-stp=2-sufoterephthalalic acid, 2,2’-bipy=2,2’-bipyridine) was obtained by hydrothermal method. The crystal structure was determined by single crystal X-ray diffraction. The complex has a one-dimensional parallel double-chain structure. Eu3+ is a nine-coordinated by six O atoms from three 2-sufoterephthalalic acids, one water molecule and two N atoms from 2,2’-bipyridine. The fluorescence properties of the complex were studied. The complex shows the characteristics narrow emission of Eu3+ ion at 581, 594, 619, 654 and 698 nm, corresponding to 5D0→7FJ (J=0～4) transitions. The strongest emission peak is at 619 nm, corresponding to 5D0→7F2 transition for red light. Different organic solvents have different effects on the fluorescence intensity of the complex, and benzaldehyde exerts the most significant fluorescence quenching effect. So, this complex can be used as a fluorescent sensing probe for benzaldehyde.