Various zirconia content in ZrO2-TiO2 mixed oxide catalysts (x = 5, 10, 20 ZrO2 wt%) were synthesized by cost-effective sol-gel process and characterized by different techniques, i.e. XRD diffraction patterns, TG-DTA analyses, FTIR spectroscopy, N-2 adsorption/desorption measurements, and TEM microscope. The investigation of the acidic/basic properties was studied by means of FTIR spectroscopy using pyridine as an adsorbed molecule. Characterization estimates exhibit that the deposition by ZrO2 improves the surface properties of TiO2 structures and increase the TiO2 surface area up to 92 m(2)/g. TEM results affirmed the homogeneous distribution of ZrO2 particles on the surface of TiO2 of particle size in the range of 12-17 nm. The performance of the prepared zirconia-titania catalysts with different concentration ratios in acridine derivates synthesis from hydroxyl-benzaldehyde was studied. The results of catalytic test reveal that, the activity of ZrO2-TiO2 catalysts was significantly enhanced by depositing an optimum amount ratio of ZrO2 reach to 10 % to raise the yield to 95, 97 and 99 %. This can be attributed to the higher its surface area and its performance as basic site catalyst in the studied test.