The effect of Fe3O4 percentage on Fe3O4-TiO2 composite for methyl orange photocatalytic degradation has been investigated. Hydrothermal was carried out on TiO2 before being combined with Fe3O4 by precipitation method. The composites were characterized by means of Scanning Electron Microscope (SEM), X-ray diffraction (XRD) and UV-Vis diffuse and reflectance spectroscopy (UV-Vis DRS). The photocatalytic activity of Fe3O4-TiO2 composites were evaluated for methyl orange degradation. The addition of Fe3O4 to TiO2 could reduce the bandgap energy. The lowest bandgap energy was obtained at 20% Fe3O4-TiO2 composite. By using this composited, the degradation of methyl orange was 90%.