Properties and characteristics of materials play important role in modern engineering design. Each property of materials is based on its transformation at inner structure; therefore, the most fundamental crystalline structure of materials needs to be understood at the first stage. Defects theory, the formation and growth of crystalline nucleus, nucleus and homogenization, solid diffusion phenomenon, hardening phenomenon, failure phenomenon and theory are also discussed in this course. The aim of this course is to acquaint students to fully understand the theory basis and characteristic transformation of metallic materials.