Nanocrystals provide a confinement effect for nanoscale engineering. In this work the cadmium selenide quantum dot and its nanoparticle films have been deposited by chemical bath deposition method (CBD). Effects of deposition time, pH and annealing operation on the optical and structural of CdSe nanoparticle film were studied. The energy band gap, structure and morphology of the samples are investigated by X-ray diffraction (XRD), UV-Vis spectrometer and scanning electron microscope (SEM). It was found that the optical band gap, nanoparticle size and thin film configuration are changed by varying pH, deposition time and annealing operation.