A new 3D coordination polymer [NH 2 (CH 3 ) 2 ] 2 [Zn 7 L 4 (DMF) 2 (H 2 O) 3 ]·19H 2 O (1) (L=2,3′,5,5′-biphenyl tetracarboxylic acid) has been solvothermally synthesized and structurally characterized by IR, elemental analysis and single-crystal X-ray diffraction. Single-crystal X-ray diffraction studies indicate that 1 exhibits 3D framework with a one-dimensional (1D) channel. The luminescence properties have been studied, and the results showed that 1 displays strong fluorescent emissions both in the solid state and in methanol suspension at room temperature. More interesting, the addition of Fe 3+ causes the fluorescence intensity of 1 to be weakened, which implies that it may be used as luminescent probes of Fe 3+ .