Zinc and cadmium are two main transition metal ions and play profound important roles in environmental and human health. But the distinctive detection of these two ions is still challenging since they belong to the same periodic group and have similar chemical properties. A fluorescent bipyridine-based porous organic polymer (Bpy-POP) containing aggregation caused quenching (ACQ) units (anthracene) and metal ions recognition units (bipyridine) was synthesized through the Schiff base condensation reaction. In the DMF/H 2 O mixtures with the water fractions of 90%, the Bpy-POP aggregated and the fluorescent Bpy-POP quenched subsequently due to the ACQ effect of anthracene in the skeleton ("OFF" state). With the addition of Zn 2+ or Cd 2+ , however, the strong coordination of the bipyridine units from the adjacent Bpy-POPs with Zn 2+ or Cd 2+ induced the partial dispersion of large Bpy-POP aggregates. Consequently, the fluorescence intensities enhanced dramatically as well as the fluorescence emission shifted to redder region, showing an "ON" state. Combing the fluorescence increasing efficiency and the maximum emission wavelength shift degree together, Zn 2+ and Cd 2+ can be selectively discriminated and quantitatively detected, which exhibits a great promising of the present Bpy-POP based method in Zn 2+ and Cd 2+ monitoring in real samples.