Via applying the mixed-ligand approach, a new Cu(II)-bearing coordination polymer (CP) with the chemical formula of [Cu(1,4-chdc)(L)(H2O)]n (1, (1,4-H2chdc = 1,4-cyclohexanedicarboxylic acid, L = 2-(4-fluorophenyl)-1H-imidazo[4,5-f][1,10]phenanthroline) has been successfully prepared under hydrothermal condition. The single-crystal X-ray diffraction study shows that CP 1 shows a 1D chain-like structure which is further extended into a 2D supramolecular network via the H-bond interactions. Furthermore, a sonochemical treatment method was applied to produce the nanosized 1 with the size distribution around 200 nm. To detect the cell proliferation of MGC-803 (human gastric cancer cell lines) after treated with nano 1, the Cell Counting Kit-8 (CCK-8) assay was performed in this experiment. Besides, the MGC-803 cell apoptosis was determined by Annexin V-FITC/PI (FITC = fluorescein isothiocyanate, PI = propidium iodide) apoptosis detection kit in flow cytometer and western blot after treated with nano 1. A new Cu(II)-bearing coordination polymer has been prepared under hydrothermal conditions. A sonochemical treatment method was applied to produce the nanosized 1 with the size distribution around 200 nm. The anti-cancer activity of nano 1 has been evaluated via the Cell Counting Kit-8 (CCK-8) assay and Annexin V-FITC/PI. [ABSTRACT FROM AUTHOR]