Cuprous oxide (Cu2O) was first investigated in the 1920s as a semiconductor material with Eg~2.17 eV. It is ideal for applications in solar cells, electrochromic devices, oxygen and humidity sensors because of its high optical absorption coefficient, non-toxic nature, abundant availability and low cost for production. Many groups have tried different ways to grow the cuprous oxide by, for instance, sputtering, CVD, PLD, MBE, and electro-deposition etc. Among them, the sputtering method is probably the most cost-effective and easy to operate. In this work, the cuprous oxide thin films were grown on R-Al2O3 and (110)-MgO substrates by DC reactive magnetron sputtering. Thin films grown at different temperatures under various oxygen partial pressures were studied by X-ray diffraction (XRD) to test their structural perfections. Samples with the Cu2O on Al2O3(1012) and MgO(110) were studied via measurement of cathodoluminescence(CL) spectroscopy, photoluminescence (PL) spectroscopy, transmission spectroscopy and magneto transport behaviors. The correlation of growth condition and physical properties are discussed.