The present invention relates to a surface treatment method for magnetic particles, a magnetic composite prepared thereby, and a magnetic composite for labeling target materials. More specifically, the invention relates to a surface treatment method for magnetic particles and a magnetic composite having excellent dispersibility prepared thereby, wherein the surface treatment method comprises the steps of: performing the acid-treatment of magnetic particles and mixing the acid-treated magnetic particles with a water-soluble solvent in order to form a hydroxyl group (-OH) on the surface of the magnetic particles and mixing the magnetic particles, in which the hydroxyl group is formed, with a surface treatment agent containing an organic ligand, which can be bonded to the hydroxyl group, so that the organic ligand is treated on the surface of the magnetic particles.
