A new co-casting method has been developed to synthesize novel mesostructured γ-Fe2O3/C composites with γ-Fe2O3 nanoparticles embedded in the wall of ordered mesoporous carbon materials. Fe3+ ions were captured by the framework of polyfurfuryl alcohol in the channel of mesoporous silica; during the carbonization process, FeCl3·6H2O was decomposed and magnetic γ-Fe2O3 nanoparticles were formed and confined in the carbon framework. The γ-Fe2O3/C composite materials were characterized using X-ray diffraction (XRD), nitrogen sorption, Mossbauer spectroscopy, X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and energy-dispersive X-ray (EDX) spectroscopy techniques; the magnetization strength was measured on a vibrating-sample magnetometer (VSM). Different amounts of magnetic iron oxides could be introduced into the composites, which led to varied specific saturation magnetizations. Near-zero coercivity and remanance indicate the superparamagnetic behavior of the composites.