Abstract: The modification of NaY by chromium ion was systemically studied.The modified CrY molecular sieve was characterized by X-ray diffraction (XRD), Fourier transform infrared spectrum (FT-IR) and nitrogen adsorption.The experimental results show that the optimum condition of modification are two times modification with 0.5 mol/L Cr³⁺at 40℃.The result of FT-IR suggested the peak disappeared at 1 147 cm^-1 and the peak generated a blue shift at 1 024 cm^-1, indicating that Cr³⁺ had exchanged Na⁺ in the framework of NaY molecular sieve.Static adsorption denitrification of a model fuel on CrY molecular sieve had carried out at different adsorption time and temperature.The results showed that the adsorption of quinoline on CrY molecular sieve was chemical adsorption and the adsorption type was coordination adsorption and π complex adsorption.The adsorption effect was better at room temperature for 30 min.The adsorption of quinoline over CrY molecular sieve belongs to Langmuir adsorption and Freundlich adsorption model.