This Diffraction Data Analysis MK contains topics that have a very important role in studying Materials Science, especially studying how to investigate and interpret the internal structure of crystalline solid materials through theoretical studies and experimental activities regarding x-ray diffraction and other empirical experiences in the form of analytical activities. data from the experimental results above, both qualitatively and quantitatively. The material of this course consists of four main parts which will be presented sequentially and coherently, first starting with a review of crystalline solid materials (abbreviated as crystals) as x-ray scattering centers, crystal geometry, lattices and bases as building blocks of crystal structures, lattice parameters, unit cells, crystal symmetry, crystal planes and determining their orientation. Second, the study of the physics of x-rays, their properties and methods of production, continuous and characteristic spectra, electron transitions in atoms which are accompanied by the emission of characteristic x-ray radiation. Third, a study of the science of x-ray diffraction by crystal atoms in order to understand the internal structure of crystalline materials, set up x-ray diffraction experiments, and access experimental data. Fourth, a theoretical study of how to analyze x-ray diffraction experimental data, both qualitatively and quantitatively using the Rietveld method and Rietica software, as well as practicing it with certain test samples.