In this paper analysed annealing effect in CdS adding Ag metals. Films fabricated by cost effective and simple rote Spin Coating Method. Ultra sonicated used for Ag doping in CdS with different concentration like 1and 5%.Prepared film annealed in vacuum oven presence of Argon gas atmosphere at high temperature 100, 200, 4000C for 20 minutes. Characterize structure and optical parameter of thin film by X-ray Diffractometer (XRD) and UV-Visible spectrometer. The micro strain, dislocation density, average crystallite sizes of the samples calculated from WH plots, Debye Scherrer and Modified Debye Scherrer formula. An obtained result remains same and near standard value 9.603nm but effectively changes with increasing temperature due to lattice compression. Optical band gap values of different samples calculated by approximate Tauc-plot method. Absorption wavelength also investigates of the sample. FTIR spectrometer uses for finding bond formation and stretching of functional groups. Photoluminescence spectrometer used for observes material imperfections and impurities. The grain size and optical band gap of Ag/CdS composite thin film change with increasing temperatures and obtained suitable range. It used for window material of solar cell