Iron cutans coated on the surface of quartz sand were synthetized at initial pH 7 and iron mole ratio R[Fe(Ⅱ)/Fe(Ⅲ)]0.1 to investigate the influence of the temperature and the aging time of the synthetic systems on the formation of iron oxides in the cutans and further providing the formation mechanism of iron cutans. The compositions and morphologies of the minerals in the synthesized cutans were determined by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The results showed that when the quartz sand amount was 10 g and the aging time was 25 d, the peak intensity of goethite in XRD patterns increased successively and the crystalline shape of iron oxide in the cutans analyzed by SEM became increasingly bigger with the increase of temperature from 30℃ to 90℃. When the quartz sand amount was 10 g and the aging temperature was 60℃, the peak intensity of goethite in XRD patterns increased successively during the first 18 days, and then decreased and tended to become stable. The crystalline shape of goethite in the cutans analyzed by SEM increased during the first 18 days and reached the maximum on the 18th day, and then decreased gradually along with the increase of aging time.