Abstract: A Fe₃O₄/chitosan magnetic composite particle loading riboflavin used as model of drug is prepared through a co-precipitation process in situ. The chemical component, morphology and magnetic property were characterized by Fourier transform infrared spectroscopy (FTIR), transmission electron microscope (TEM), field emission scanning electron microscopy (FESEM) and vibrating sample magnetometer (VSM), respectively. The results show that the diameter of a typical Fe₃O₄/chitosan composite particle is about 40 nm and the distribution is uniform, the average magnetic response time is 52 s, and the strength of saturation magnetization is 3.313 2 A·m²·kg^-1. The drug content (mass fraction), the drug loading efficiency and the in vitro release profiles under simulated gastric fluid, simulated intestinal fluid, saline, glucose solution using in medicine and redistilled water were investigated using UV/Vis spectrophotometry, respectively. The results show that the drug content is about 9.9%, the drug loading efficiency reaches 70.8%, and the Fe₃O₄/chitosan composite particle displays an excellent drug controlled release behavior under the experimental conditions of the simulated intestinal fluid. Less than 16.06% of the drug is released from composite particle after 10 h but up to 52.18% after 60 h.