This course is designed for senior undergraduates and first-year graduate students majoring in physics, materials science, chemistry, and electrical engineering. The course mainly covers the following topics: crystalline structure and chemical bond fundamental of materials especially inorganic crystals, relationship between chemical bonds and band structures, fundamental of Density functional theory(DFT), and applications of the powerful density-functional approach in understanding the structure-property relationship of materials for physics and materials science research. The topics makes it possible for students and junior researchers to apply this important DFT-based computational technique to a broad range of physics and materials science problems. We will also spend some time in explaining the fundamental of density functional theory and the related software packages for real applications.