Abstract: Zirconium oxybenzoate precursor was obtained with the rheological phase reaction.Characterization results of element analysis,IR,TG and DTA indicate the precursor is ZrO(C_6H_5COO)_2·2H_2O.After heating(1.5) hours at 700 ℃ in nitrogen atmosphere the precursor decomposed into nanometer ZrO_2 of high purity,The ZrO_2 crystallines have hexagonal structure with spherical mophology and an average size of 20 nm.With this ZrO_2 as catalyst,p-NCB and the pH of the solution on the degradation of p-NCB were tested.Th...