Photosensitive n-CdO/p-InSe heterojunctions were developed and studied for the rst time. The heterojunctions were fabricated by dc reactive magnetron sputtering of CdO thin lms onto the freshly cleaved p-InSe single-crystal substrates (0 0 1). Surface morphology of the obtained lms was studied by means of atomic force microscopy. From the X-ray diraction result it is shown that the CdO lm is polycrystalline with cubic structure. The mechanisms of current transport through the space-charge region under forward and back biases were established by investigation of temperature dependences of the IV characteristics. The main photoelectric parameters and the photosensitivity spectra were measured at room temperature.