Cadmium selenide nanocrystals were synthesized with mercaptoacteic acid as stabilizer and different size of nanocrystals from 2nm to 3nm were obtained by size selective precipitation.The optical properties of CdSe nanoclusters were studied by optical absorption

photoluminescence (PL) and photoluminescence excitation(PLE) spectroscopies at room temperature.The UV-vis absorption spectroscopy shows sharp absorption spectra with clear excitonic features which indicating a narrow size distribution for our samples.Photoluminescence investigation shows that our samples have two luminescence bands

a sharp high energy hand with high intensity near the absorption edge attributed to radiative recombination of electron hole pairs after relaxation to lowest quantum dot level

and the other lower energy broad band is attributed to the trapping center at the matrix interface region.More than one band appeared in the photoluminescence excitation (PLE) spectra

assigned to S-S and P-P transition.The luminescence properties obtained for different excitation are also presented.