Mn2+ - doped zinc selenide (ZnSe:Mn) nanomaterials have been attracted much attention in recent years for fundamental properties and technological applications. In this work, ZnSe:Mn luminescent nanomaterials were successfully synthesized by co-precipitate method in gather colloidal environment mecapto acetic acid at room temperature. The morphology and the structure of the prepared sa~ples were characterized by field emission scanning electron microscopy (FESEM) and X-ray difftaction (XRD). FESEM images and XRD diagrams showed that the materials are in size of 20-50 nm with single phase structure of ZnSe. Photoluminescence of materials was measured at room temperature by an IHR 550 spectrometer using an excitation laser with 266 nm wavelength. It shows that ZnSe:Mn nanoparticles materials have strong emission in orange region (with a maximum at 645 nm) which correspond to the 4T16A, transition of Mn2+.