Abstract: Arsanilic acid magnetic molecularly imprinted polymer (MIP) was synthesized by surface polymerization technique using arsanilic acid (ASA) as template molecule, 2-vinyl pyridine (2-VP) as functional monomer selected by UV-vis absorption spectra and denatured Fe₃O₄@SiO₂ as the carrier. The structure and composition of the compound were characterized by infrared spectroscopy, and the properties of the compound were studied by static, dynamic and selective adsorption tests. As shown by the results, MIP had good adsorption properties for ASA, and its maximum quantity of adsorption was 5.17 g·kg^-1. ASA in chicken liver was separated, enriched and determined using MIP as solid phase extraction packing, combined with high performance liquid chromatography. Detection limit (3S/N) of the method was 1.10×10^-3mg·kg^-1,and test for recovery was made by standard addition method, giving results in the range of 82.1%-94.7%, with average RSD (n=5) of 3.4%.