Molecular imprinted polymers（MIPs） play a important role in the separation and enrichment of trace substances due to their specific recognition capability．In this paper，a method for preparing porous magnetic MIPs（mMIPs） microspheres was developed via the oil-in-water soap-free liquid emulsification technique to cope with a widely used pesticide ,α,-naphthylacetic（NAA）．The preparation was done by simply mixing methacrylic acid－styrene polymer precursor，NAA，Fe,3,O,4, magnetic fluid and 2，2-azobisisobutyronitrile together in one pot．The product was characterized by scanning electron microscopy，transmission electron microscopy and Fourier transform infrared spectroscopy，respectively．The results showed that it is a kind of microspheres with a size distribution about 80 μm．And there are lots of pores distributed in/on the particle with diameters ranging from 1 to 10 μm．Such a porous structure could effectively increase the specific surface area，the number of contact recognition sites and the column capacity of the MIPs，as well as the mass transfer rate．Adsorption kinetics experiments showed that the adsorption equilibrium could be reached in 120 minutes．Meanwhile，the results of the adsorption isotherms and Scatchard analysis revealed that there exist two type of affinity binding sites for NAA in the MIPs．The dissociation constant and apparent maximum binding capacity were found to be －128.20 µg·mL,－1, and －19.50 mg·g,－1, for the low affinity binding site，and 161.30 µg·mL,－1, and 29.35 mg·g,－1, for the high affinity binding site．As comparison，there only existed one type affinity binding site for none-imprinted MIPs with the dissociation constant and apparent maximum binding capacity of 61.39 µg·mL,－1, and 4.658 mg·g,－1,，respectively．Moreover，the results of the adsorption kinetics studies confirmed that the adsorption process matched the pseudo-second-order kinetic model well，indicating that it was controlled mainly by chemical adsorption．All results demonstrated the high specificity of mMIPs towards NAA．To investigate the feasibility of the mMIPs，they were used in the determination of NAA in real sample of tomato juice by high performance liquid chromatography with UV－Vis detector．The average recoveries for the sample at three spiked levels ranged from 78.7% to 89.2%，with relative standard deviations（RSDs） less than 3.9%（,n ,= 3）．Notably，the average recoveries still could reach 80.3% even when the amount of NAA in tomato juice is only 0.005 μg·mL,－1, which is far lower than the maximum residue limits of NAA stipulated by GB and the European Union（100 and 60 μg·kg,－1,，respectively）．All experimental results indicated that it was readily to perform the preparation with the proposed method，and the mMIPs exhibited many merits，including the high selectivity and specificity for NAA，the fast mass transfer rate and the easy operation．With the MIPs，the high matrix effects of real samples could be eliminated effectively，and the accuracy and reliability could be improved significantly for NAA determination in practice.