CdSe thin film was produced via chemical bath deposition at 50 degrees C. Transmittance, absorption, optical band gap and refractive index have been investigated via UV/VIS. Spectrum. The hexagonal form has been observed as one of the structural properties in XRD. The structural and optical properties of CdSe thin films, which have been produced at different pH, were analyzed. SEM analyses have been performed; surface analyses of the films were made accordingly. Some properties of the films have been changed with pH and these properties have been investigated. Tested pH values were at range 7-10. The optical band gap has been changed with the pH of the bath, taking values between 1.76 and 2.09eV. Also, film thickness was measured as 74.65, 106.39, 107.95 and 138.15 nm for the films produces at pH: 7, 8, 9 and 10, respectively.