Abstarct: In this research we have studied the surface morphology, structural, optical, electrical properties and also the photoconductivity effect of nanostructured copper oxide (CuO) thin films grown by thermal oxidation method on various substrates including: Cu-foil, glass, FTO and ITO. In physical characterization of the samples we used field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), optical spectroscopy (UV-Vis.), current-voltage (I-V) measurement. Through the study of photoconductivity effect blue and red LED lamp were used. In CuO laxyer preparation on Cu-foil by thermal oxidation technique, samples were annealed in the presence of air atmosphere at 400, 500 and 600 ◦C for 2, 3 and 4 h (section 4-2). Also the Cu-foils were annealed through two heating processes: "continuous" and "steps" in the temperature range of 400-500 ○C and 400-600 ○C in air atmosphere (section 4-3). For laxyer preparation on glass, FTO and ITO substrates, samples were studied under two cases: with and without adhesive laxyer (section 4-4). It should be noted that samples in sections (4-3) and (4-4) are studied for photoconductivity effect response. In general, the FESEM images of the synthesized samples indicate the formation of nanowires on Cu-foil substrate, and nanograins on glass, FTO and ITO substrates. The results of x-ray diffraction patterns indicate the formation of the polycrystalline structure in monoclinic phase with preferred direction of (-111) for samples grown on Cu-foil substrate, and for samples grown on other substrates with the main orientation of (111). The photoconductivity effect indicated that the surface morphology, crystallite size and electrical conductivity of the laxyers are the main effective parameters in CuO baxsed photo-sensitive devices.