Undoped CaCu3Ti4O12 thin film and nickel doped CaCu3-xNixTi4O12 (CCNTO) thin film with x =0.10, 0.20 and 0.30 were prepared by sol-gel method.The effects of NiO on the dielectric properties and microstructure revolution of CCTO were studied.The crystalline structure and the surface morphology of the films were markedly affected by the variety NiO content.AFM micrographs of the CaCu3-xNixTi4O12 samples showed that the grain size of Ni-doped CCTO was smaller than the grain size of CCTO without Ni doped.When x =0.2, the lowest leakage current was obtained and the minimum value reached to 0.564 mA, meanwhile, the highest threshold voltage and nonlinear coefficient were found, where the maximum values of them were 81V/mm and 1.9 respectively.The dielectric constant increased when the doping concentration of Ni reached a certain level, however, the dielectric loss increased in the mass.