Lead Selenide (PbSe) nanostructures are one of the best candidates which can be used in modern optic devices. It can be deposited by various methods. Optical absorbance spectra of PbSe quantum dots were collected with an UV/Vis/NIR spectrometer. In this paper, the details of UV-Visible features of PbSe quantum dots (QDs) are discussed and the effect of particle size on absorption peak (edge) was studied. It will be shown that the absorption peak of PbSe QDs undergoes red-shift with increasing particle size.